Merged scons/scons into default

120 files changed, 1098 insertions, 956 deletions

diff --git a/src/engine/SCons/Action.py b/src/engine/SCons/Action.py
index 4dfde31..7e1f8f1 100644
--- a/src/engine/SCons/Action.py
+++ b/src/engine/SCons/Action.py
@@ -101,7 +101,6 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import dis
 import os
-# compat layer imports "cPickle" for us if it's available.
 import pickle
 import re
 import sys
@@ -163,12 +162,12 @@ def _callable_contents(obj):
     """
     try:
         # Test if obj is a method.
-        return _function_contents(obj.im_func)
+        return _function_contents(obj.__func__)
 
     except AttributeError:
         try:
             # Test if obj is a callable object.
-            return _function_contents(obj.__call__.im_func)
+            return _function_contents(obj.__call__.__func__)
 
         except AttributeError:
             try:
@@ -188,12 +187,12 @@ def _object_contents(obj):
     """
     try:
         # Test if obj is a method.
-        return _function_contents(obj.im_func)
+        return _function_contents(obj.__func__)
 
     except AttributeError:
         try:
             # Test if obj is a callable object.
-            return _function_contents(obj.__call__.im_func)
+            return _function_contents(obj.__call__.__func__)
 
         except AttributeError:
             try:
@@ -234,8 +233,8 @@ def _code_contents(code):
 
     # The code contents depends on the number of local variables
     # but not their actual names.
-    contents.append("%s,%s" % (code.co_argcount, len(code.co_varnames)))
-    contents.append(",%s,%s" % (len(code.co_cellvars), len(code.co_freevars)))
+    contents.append(b"{}, {}".format(code.co_argcount, len(code.co_varnames)))
+    contents.append(b", {}, {}".format(len(code.co_cellvars), len(code.co_freevars)))
 
     # The code contents depends on any constants accessed by the
     # function. Note that we have to call _object_contents on each
@@ -245,43 +244,43 @@ def _code_contents(code):
     # Note that we also always ignore the first entry of co_consts
     # which contains the function doc string. We assume that the
     # function does not access its doc string.
-    contents.append(',(' + ','.join(map(_object_contents,code.co_consts[1:])) + ')')
+    contents.append(b',(' + b','.join(map(_object_contents,code.co_consts[1:])) + b')')
 
     # The code contents depends on the variable names used to
     # accessed global variable, as changing the variable name changes
     # the variable actually accessed and therefore changes the
     # function result.
-    contents.append(',(' + ','.join(map(_object_contents,code.co_names)) + ')')
+    contents.append(b',(' + b','.join(map(_object_contents,code.co_names)) + b')')
 
 
     # The code contents depends on its actual code!!!
-    contents.append(',(' + str(remove_set_lineno_codes(code.co_code)) + ')')
+    contents.append(b',(' + remove_set_lineno_codes(code.co_code) + b')')
 
-    return ''.join(contents)
+    return b''.join(contents)
 
 
 def _function_contents(func):
     """Return the signature contents of a function."""
 
-    contents = [_code_contents(func.func_code)]
+    contents = [_code_contents(func.__code__)]
 
     # The function contents depends on the value of defaults arguments
-    if func.func_defaults:
-        contents.append(',(' + ','.join(map(_object_contents,func.func_defaults)) + ')')
+    if func.__defaults__:
+        contents.append(b',(' + b','.join(map(_object_contents,func.__defaults__)) + b')')
     else:
-        contents.append(',()')
+        contents.append(b',()')
 
     # The function contents depends on the closure captured cell values.
-    closure = func.func_closure or []
+    closure = func.__closure__ or []
 
     #xxx = [_object_contents(x.cell_contents) for x in closure]
     try:
         xxx = [_object_contents(x.cell_contents) for x in closure]
     except AttributeError:
         xxx = []
-    contents.append(',(' + ','.join(xxx) + ')')
+    contents.append(b',(' + ','.join(xxx).encode('ascii') + b')')
 
-    return ''.join(contents)
+    return b''.join(contents)
 
 
 def _actionAppend(act1, act2):
@@ -362,7 +361,7 @@ def _do_create_action(act, kw):
         # The list of string commands may include a LazyAction, so we
         # reprocess them via _do_create_list_action.
         return _do_create_list_action(commands, kw)
-    
+
     if is_List(act):
         return CommandAction(act, **kw)
 
@@ -411,8 +410,8 @@ class ActionBase(object):
     other objects (Builders, Executors, etc.)  This provides the
     common methods for manipulating and combining those actions."""
 
-    def __cmp__(self, other):
-        return cmp(self.__dict__, other)
+    def __eq__(self, other):
+        return self.__dict__ == other
 
     def no_batch_key(self, env, target, source):
         return None
@@ -424,6 +423,7 @@ class ActionBase(object):
 
     def get_contents(self, target, source, env):
         result = [ self.get_presig(target, source, env) ]
+        result = [ SCons.Util.to_bytes(r) for r in result ]
         # This should never happen, as the Action() factory should wrap
         # the varlist, but just in case an action is created directly,
         # we duplicate this check here.
@@ -431,8 +431,8 @@ class ActionBase(object):
         if is_String(vl): vl = (vl,)
         for v in vl:
             # do the subst this way to ignore $(...$) parts:
-            result.append(env.subst_target_source('${'+v+'}', SCons.Subst.SUBST_SIG, target, source))
-        return ''.join(result)
+            result.append(SCons.Util.to_bytes(env.subst_target_source('${'+v+'}', SCons.Subst.SUBST_SIG, target, source)))
+        return b''.join(result)
 
     def __add__(self, other):
         return _actionAppend(self, other)
@@ -504,7 +504,7 @@ class _ActionAction(ActionBase):
         # This code assumes s is a regular string, but should
         # work if it's unicode too.
         try:
-            sys.stdout.write(unicode(s + "\n"))
+            sys.stdout.write(s + u"\n")
         except UnicodeDecodeError:
             sys.stdout.write(s + "\n")
 
@@ -664,7 +664,7 @@ def _subproc(scons_env, cmd, error = 'ignore', **kw):
 
     try:
         return subprocess.Popen(cmd, **kw)
-    except EnvironmentError, e:
+    except EnvironmentError as e:
         if error == 'raise': raise
         # return a dummy Popen instance that only returns error
         class dummyPopen(object):
@@ -1052,11 +1052,11 @@ class FunctionAction(_ActionAction):
             rsources = list(map(rfile, source))
             try:
                 result = self.execfunction(target=target, source=rsources, env=env)
-            except KeyboardInterrupt, e:
+            except KeyboardInterrupt as e:
                 raise
-            except SystemExit, e:
+            except SystemExit as e:
                 raise
-            except Exception, e:
+            except Exception as e:
                 result = e
                 exc_info = sys.exc_info()
 
@@ -1126,7 +1126,7 @@ class ListAction(ActionBase):
 
         Simple concatenation of the signatures of the elements.
         """
-        return "".join([x.get_contents(target, source, env) for x in self.list])
+        return b"".join([x.get_contents(target, source, env) for x in self.list])
 
     def __call__(self, target, source, env, exitstatfunc=_null, presub=_null,
                  show=_null, execute=_null, chdir=_null, executor=None):
@@ -1171,11 +1171,11 @@ class ActionCaller(object):
         actfunc = self.parent.actfunc
         try:
             # "self.actfunc" is a function.
-            contents = str(actfunc.func_code.co_code)
+            contents = str(actfunc.__code__.co_code)
         except AttributeError:
             # "self.actfunc" is a callable object.
             try:
-                contents = str(actfunc.__call__.im_func.func_code.co_code)
+                contents = str(actfunc.__call__.__func__.__code__.co_code)
             except AttributeError:
                 # No __call__() method, so it might be a builtin
                 # or something like that.  Do the best we can.
diff --git a/src/engine/SCons/ActionTests.py b/src/engine/SCons/ActionTests.py
index 631d7c1..3eee4b6 100644
--- a/src/engine/SCons/ActionTests.py
+++ b/src/engine/SCons/ActionTests.py
@@ -61,7 +61,7 @@ test = TestCmd.TestCmd(workdir = '')
 test.write('act.py', """\
 import os, string, sys
 f = open(sys.argv[1], 'w')
-f.write("act.py: '" + string.join(sys.argv[2:], "' '") + "'\\n")
+f.write("act.py: '" + "' '".join(sys.argv[2:]) + "'\\n")
 try:
     if sys.argv[3]:
         f.write("act.py: '" + os.environ[sys.argv[3]] + "'\\n")
@@ -265,7 +265,7 @@ def test_positional_args(pos_callback, cmd, **kw):
         """Test handling of bad cmdstrfunc arguments """
         try:
             a = SCons.Action.Action(cmd, [], **kw)
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             s = str(e)
             m = 'Invalid command display variable'
             assert s.find(m) != -1, 'Unexpected string:  %s' % s
@@ -488,7 +488,7 @@ class _ActionActionTestCase(unittest.TestCase):
         def func(): pass
         try:
             a = SCons.Action.Action('foo', cmdstr='string', strfunction=func)
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             s = str(e)
             m = 'Cannot have both strfunction and cmdstr args to Action()'
             assert s.find(m) != -1, 'Unexpected string:  %s' % s
@@ -556,7 +556,7 @@ class _ActionActionTestCase(unittest.TestCase):
                 assert isinstance(source, list), type(source)
                 return 9
             b = SCons.Action.Action([firstfunc, execfunc, lastfunc])
-            
+
             sio = io.StringIO()
             sys.stdout = sio
             result = a("out", "in", env)
@@ -699,7 +699,7 @@ class _ActionActionTestCase(unittest.TestCase):
             env['PRINT_CMD_LINE_FUNC'] = my_print_cmd_line
             a("output", "input", env)
             assert result == ["execfunc(['output'], ['input'])"], result
-            
+
 
         finally:
             sys.stdout = save_stdout
@@ -942,7 +942,7 @@ class CommandActionTestCase(unittest.TestCase):
 
         act = SCons.Action.CommandAction('xyzzy $TARGETS $SOURCES',
                                          cmdstr='cmdstr\t$TARGETS\n$SOURCES   ')
-                    
+
         s = act.strfunction([], [], env)
         assert s == 'cmdstr\t\n   ', s
         s = act.strfunction([t1], [s1], env)
@@ -1246,7 +1246,7 @@ class CommandActionTestCase(unittest.TestCase):
         c = a.get_contents(target=[], source=[],
                            env=Environment(foo = 'FFF', bar = 'BBB',
                                            baz = CmdGen))
-        assert c == "| | FFF BBB 1", c
+        assert c == b"| | FFF BBB 1", c
 
         # Make sure that CommandActions use an Environment's
         # subst_target_source() method for substitution.
@@ -1257,7 +1257,7 @@ class CommandActionTestCase(unittest.TestCase):
         c = a.get_contents(target=DummyNode('ttt'), source = DummyNode('sss'),
                            env=SpecialEnvironment(foo = 'GGG', bar = 'CCC',
                                                   baz = 'ZZZ'))
-        assert c == 'subst_target_source: | $( $foo | $bar $) | $baz 1', c
+        assert c == b'subst_target_source: | $( $foo | $bar $) | $baz 1', c
 
         # We've discussed using the real target and source names in a
         # CommandAction's signature contents.  This would have have the
@@ -1274,35 +1274,35 @@ class CommandActionTestCase(unittest.TestCase):
 
         a = SCons.Action.CommandAction(["$TARGET"])
         c = a.get_contents(target=t, source=s, env=env)
-        assert c == "t1", c
+        assert c == b"t1", c
 
         a = SCons.Action.CommandAction(["$TARGETS"])
         c = a.get_contents(target=t, source=s, env=env)
-        assert c == "t1 t2 t3 t4 t5 t6", c
+        assert c == b"t1 t2 t3 t4 t5 t6", c
 
         a = SCons.Action.CommandAction(["${TARGETS[2]}"])
         c = a.get_contents(target=t, source=s, env=env)
-        assert c == "t3", c
+        assert c == b"t3", c
 
         a = SCons.Action.CommandAction(["${TARGETS[3:5]}"])
         c = a.get_contents(target=t, source=s, env=env)
-        assert c == "t4 t5", c
+        assert c == b"t4 t5", c
 
         a = SCons.Action.CommandAction(["$SOURCE"])
         c = a.get_contents(target=t, source=s, env=env)
-        assert c == "s1", c
+        assert c == b"s1", c
 
         a = SCons.Action.CommandAction(["$SOURCES"])
         c = a.get_contents(target=t, source=s, env=env)
-        assert c == "s1 s2 s3 s4 s5 s6", c
+        assert c == b"s1 s2 s3 s4 s5 s6", c
 
         a = SCons.Action.CommandAction(["${SOURCES[2]}"])
         c = a.get_contents(target=t, source=s, env=env)
-        assert c == "s3", c
+        assert c == b"s3", c
 
         a = SCons.Action.CommandAction(["${SOURCES[3:5]}"])
         c = a.get_contents(target=t, source=s, env=env)
-        assert c == "s4 s5", c
+        assert c == b"s4 s5", c
 
 class CommandGeneratorActionTestCase(unittest.TestCase):
 
@@ -1419,7 +1419,7 @@ class CommandGeneratorActionTestCase(unittest.TestCase):
                           ignore = 'foo', test=test)
         a = self.factory(f)
         c = a.get_contents(target=[], source=[], env=env)
-        assert c == "guux FFF BBB test", c
+        assert c == b"guux FFF BBB test", c
 
     def test_get_contents_of_function_action(self):
         """Test contents of a CommandGeneratorAction-generated FunctionAction
@@ -1429,13 +1429,13 @@ class CommandGeneratorActionTestCase(unittest.TestCase):
             pass
 
         func_matches = [
-            "0,0,0,0,(),(),(d\000\000S),(),()",
-            "0,0,0,0,(),(),(d\x00\x00S),(),()",
+            b"0, 0, 0, 0,(),(),(d\000\000S),(),()",
+            b"0, 0, 0, 0,(),(),(d\x00\x00S),(),()",
             ]
-        
+
         meth_matches = [
-            "1,1,0,0,(),(),(d\000\000S),(),()",
-            "1,1,0,0,(),(),(d\x00\x00S),(),()",
+            b"1, 1, 0, 0,(),(),(d\000\000S),(),()",
+            b"1, 1, 0, 0,(),(),(d\x00\x00S),(),()",
         ]
 
         def f_global(target, source, env, for_signature):
@@ -1460,7 +1460,7 @@ class CommandGeneratorActionTestCase(unittest.TestCase):
         def f_local(target, source, env, for_signature):
             return SCons.Action.Action(LocalFunc, varlist=['XYZ'])
 
-        matches_foo = [x + "foo" for x in func_matches]
+        matches_foo = [x + b"foo" for x in func_matches]
 
         a = self.factory(f_global)
         c = a.get_contents(target=[], source=[], env=env)
@@ -1588,13 +1588,13 @@ class FunctionActionTestCase(unittest.TestCase):
             pass
 
         func_matches = [
-            "0,0,0,0,(),(),(d\000\000S),(),()",
-            "0,0,0,0,(),(),(d\x00\x00S),(),()",
+            b"0, 0, 0, 0,(),(),(d\000\000S),(),()",
+            b"0, 0, 0, 0,(),(),(d\x00\x00S),(),()",
             ]
-        
+
         meth_matches = [
-            "1,1,0,0,(),(),(d\000\000S),(),()",
-            "1,1,0,0,(),(),(d\x00\x00S),(),()",
+            b"1, 1, 0, 0,(),(),(d\000\000S),(),()",
+            b"1, 1, 0, 0,(),(),(d\x00\x00S),(),()",
         ]
 
         def factory(act, **kw):
@@ -1608,7 +1608,7 @@ class FunctionActionTestCase(unittest.TestCase):
         c = a.get_contents(target=[], source=[], env=Environment())
         assert c in func_matches, repr(c)
 
-        matches_foo = [x + "foo" for x in func_matches]
+        matches_foo = [x + b"foo" for x in func_matches]
 
         a = factory(GlobalFunc, varlist=['XYZ'])
         c = a.get_contents(target=[], source=[], env=Environment())
@@ -1626,10 +1626,10 @@ class FunctionActionTestCase(unittest.TestCase):
 
         class Foo(object):
             def get_contents(self, target, source, env):
-                return 'xyzzy'
+                return b'xyzzy'
         a = factory(Foo())
         c = a.get_contents(target=[], source=[], env=Environment())
-        assert c == 'xyzzy', repr(c)
+        assert c == b'xyzzy', repr(c)
 
         class LocalClass(object):
             def LocalMethod(self):
@@ -1740,7 +1740,7 @@ class ListActionTestCase(unittest.TestCase):
                                      "z"])
         c = a.get_contents(target=[], source=[], env=Environment(s = self))
         assert self.foo==1, self.foo
-        assert c == "xyz", c
+        assert c == b"xyz", c
 
 class LazyActionTestCase(unittest.TestCase):
     def test___init__(self):
@@ -1791,7 +1791,7 @@ class LazyActionTestCase(unittest.TestCase):
         a = SCons.Action.Action("${FOO}")
         env = Environment(FOO = [["This", "is", "a", "test"]])
         c = a.get_contents(target=[], source=[], env=env)
-        assert c == "This is a test", c
+        assert c == b"This is a test", c
 
     def test_get_contents_of_function_action(self):
         """Test fetching the contents of a lazy-evaluation FunctionAction
@@ -1801,13 +1801,13 @@ class LazyActionTestCase(unittest.TestCase):
             pass
 
         func_matches = [
-            "0,0,0,0,(),(),(d\000\000S),(),()",
-            "0,0,0,0,(),(),(d\x00\x00S),(),()",
+            b"0, 0, 0, 0,(),(),(d\000\000S),(),()",
+            b"0, 0, 0, 0,(),(),(d\x00\x00S),(),()",
             ]
-        
+
         meth_matches = [
-            "1,1,0,0,(),(),(d\000\000S),(),()",
-            "1,1,0,0,(),(),(d\x00\x00S),(),()",
+            b"1, 1, 0, 0,(),(),(d\000\000S),(),()",
+            b"1, 1, 0, 0,(),(),(d\x00\x00S),(),()",
         ]
 
         def factory(act, **kw):
@@ -1824,7 +1824,7 @@ class LazyActionTestCase(unittest.TestCase):
         c = a.get_contents(target=[], source=[], env=env)
         assert c in func_matches, repr(c)
 
-        matches_foo = [x + "foo" for x in func_matches]
+        matches_foo = [x + b"foo" for x in func_matches]
 
         env = Environment(FOO = factory(GlobalFunc, varlist=['XYZ']))
         c = a.get_contents(target=[], source=[], env=env)
@@ -1851,8 +1851,8 @@ class ActionCallerTestCase(unittest.TestCase):
             pass
 
         matches = [
-            "d\000\000S",
-            "d\x00\x00S"
+            b"d\000\000S",
+            b"d\x00\x00S"
         ]
 
         af = SCons.Action.ActionFactory(GlobalFunc, strfunc)
@@ -1866,8 +1866,8 @@ class ActionCallerTestCase(unittest.TestCase):
         assert c in matches, repr(c)
 
         matches = [
-            'd\000\000S',
-            "d\x00\x00S"
+            b'd\000\000S',
+            b"d\x00\x00S"
         ]
 
         class LocalActFunc(object):
@@ -1885,8 +1885,8 @@ class ActionCallerTestCase(unittest.TestCase):
         assert c in matches, repr(c)
 
         matches = [
-            "<built-in function str>",
-            "<type 'str'>",
+            b"<built-in function str>",
+            b"<type 'str'>",
         ]
 
         af = SCons.Action.ActionFactory(str, strfunc)
@@ -1999,16 +1999,16 @@ class ActionCompareTestCase(unittest.TestCase):
         especially two builders that can generate the same suffix,
         where one of the builders has a suffix dictionary with a None
         key."""
-        
+
         foo = SCons.Builder.Builder(action = '$FOO', suffix = '.foo')
         bar = SCons.Builder.Builder(action = {}, suffix={None:'.bar'})
         bar.add_action('.cow', "$MOO")
         dog = SCons.Builder.Builder(suffix = '.bar')
-        
+
         env = Environment( BUILDERS = {'FOO' : foo,
                                        'BAR' : bar,
                                        'DOG' : dog} )
-        
+
         assert foo.get_name(env) == 'FOO', foo.get_name(env)
         assert bar.get_name(env) == 'BAR', bar.get_name(env)
         assert dog.get_name(env) == 'DOG', dog.get_name(env)
diff --git a/src/engine/SCons/Builder.py b/src/engine/SCons/Builder.py
index 80dcaca..50e85ec 100644
--- a/src/engine/SCons/Builder.py
+++ b/src/engine/SCons/Builder.py
@@ -166,7 +166,7 @@ class DictCmdGenerator(SCons.Util.Selector):
 
         try:
             ret = SCons.Util.Selector.__call__(self, env, source, ext)
-        except KeyError, e:
+        except KeyError as e:
             raise UserError("Ambiguous suffixes after environment substitution: %s == %s == %s" % (e.args[0], e.args[1], e.args[2]))
         if ret is None:
             raise UserError("While building `%s' from `%s': Don't know how to build from a source file with suffix `%s'.  Expected a suffix in this list: %s." % \
@@ -344,8 +344,11 @@ class EmitterProxy(object):
         return (target, source)
 
 
-    def __cmp__(self, other):
-        return cmp(self.var, other.var)
+    def __eq__(self, other):
+        return self.var == other.var
+
+    def __lt__(self, other):
+        return self.var < other.var
 
 class BuilderBase(object):
     """Base class for Builders, objects that create output
@@ -423,6 +426,9 @@ class BuilderBase(object):
     def __nonzero__(self):
         raise InternalError("Do not test for the Node.builder attribute directly; use Node.has_builder() instead")
 
+    def __bool__(self):
+        return self.__nonzero__()
+
     def get_name(self, env):
         """Attempts to get the name of the Builder.
 
@@ -440,8 +446,8 @@ class BuilderBase(object):
             except AttributeError:
                 return str(self.__class__)
 
-    def __cmp__(self, other):
-        return cmp(self.__dict__, other.__dict__)
+    def __eq__(self, other):
+        return self.__dict__ == other.__dict__
 
     def splitext(self, path, env=None):
         if not env:
diff --git a/src/engine/SCons/BuilderTests.py b/src/engine/SCons/BuilderTests.py
index 3eca588..1e544a1 100644
--- a/src/engine/SCons/BuilderTests.py
+++ b/src/engine/SCons/BuilderTests.py
@@ -20,6 +20,7 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -145,8 +146,8 @@ class Environment(object):
         d['SOURCES'] = ['__s1__', '__s2__', '__s3__', '__s4__', '__s5__', '__s6__']
         d['SOURCE'] = d['SOURCES'][0]
         return d
-    def __cmp__(self, other):
-        return cmp(self.scanner, other.scanner) or cmp(self.d, other.d)
+    def __eq__(self, other):
+        return self.scanner == other.scanner or self.d == other.d
 
 class MyAction(object):
     def __init__(self, action):
@@ -327,7 +328,7 @@ class BuilderTestCase(unittest.TestCase):
         flag = 0
         try:
             target = builder(env, None, source=n20)
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             flag = 1
         assert flag, "UserError should be thrown if a source node can't create a target."
 
@@ -343,7 +344,7 @@ class BuilderTestCase(unittest.TestCase):
                                         suffix = '.s')
         try:
             builder(env, target = 'n22', source = 'n22')
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             pass
         else:
             raise Exception("Did not catch expected UserError.")
@@ -1499,11 +1500,12 @@ class CompositeBuilderTestCase(unittest.TestCase):
         flag = 0
         try:
             builder(env, target='test3', source=['test2.bar', 'test1.foo'])[0]
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             flag = 1
+            err = e
         assert flag, "UserError should be thrown when we call a builder with files of different suffixes."
         expect = "While building `['test3']' from `test1.foo': Cannot build multiple sources with different extensions: .bar, .foo"
-        assert str(e) == expect, e
+        assert str(err) == expect, err
 
     def test_source_ext_match(self):
         """Test the CompositeBuilder source_ext_match argument"""
@@ -1530,8 +1532,8 @@ class CompositeBuilderTestCase(unittest.TestCase):
         try:
             tgt.build()
             flag = 1
-        except SCons.Errors.UserError, e:
-            print e
+        except SCons.Errors.UserError as e:
+            print(e)
             flag = 0
         assert flag, "It should be possible to define actions in composite builders using variables."
         env['FOO_SUFFIX'] = '.BAR2'
@@ -1583,47 +1585,52 @@ class CompositeBuilderTestCase(unittest.TestCase):
         flag = 0
         try:
             builder(env, target='t5', source=['test5a.foo', 'test5b.inb'])[0]
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             flag = 1
+            err = e
         assert flag, "UserError should be thrown when we call a builder with files of different suffixes."
         expect = "While building `['t5']' from `test5b.bar': Cannot build multiple sources with different extensions: .foo, .bar"
-        assert str(e) == expect, e
+        assert str(err) == expect, err
 
         flag = 0
         try:
             builder(env, target='t6', source=['test6a.bar', 'test6b.ina'])[0]
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             flag = 1
+            err = e
         assert flag, "UserError should be thrown when we call a builder with files of different suffixes."
         expect = "While building `['t6']' from `test6b.foo': Cannot build multiple sources with different extensions: .bar, .foo"
-        assert str(e) == expect, e
+        assert str(err) == expect, err
 
         flag = 0
         try:
             builder(env, target='t4', source=['test4a.ina', 'test4b.inb'])[0]
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             flag = 1
+            err = e
         assert flag, "UserError should be thrown when we call a builder with files of different suffixes."
         expect = "While building `['t4']' from `test4b.bar': Cannot build multiple sources with different extensions: .foo, .bar"
-        assert str(e) == expect, e
+        assert str(err) == expect, err
 
         flag = 0
         try:
             builder(env, target='t7', source=[env.fs.File('test7')])[0]
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             flag = 1
+            err = e
         assert flag, "UserError should be thrown when we call a builder with files of different suffixes."
         expect = "While building `['t7']': Cannot deduce file extension from source files: ['test7']"
-        assert str(e) == expect, e
+        assert str(err) == expect, err
 
         flag = 0
         try:
             builder(env, target='t8', source=['test8.unknown'])[0]
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             flag = 1
+            err = e
         assert flag, "UserError should be thrown when we call a builder target with an unknown suffix."
         expect = "While building `['t8']' from `['test8.unknown']': Don't know how to build from a source file with suffix `.unknown'.  Expected a suffix in this list: ['.foo', '.bar']."
-        assert str(e) == expect, e
+        assert str(err) == expect, err
 
 if __name__ == "__main__":
     suite = unittest.TestSuite()
diff --git a/src/engine/SCons/CacheDirTests.py b/src/engine/SCons/CacheDirTests.py
index 82fba8f..8a52928 100644
--- a/src/engine/SCons/CacheDirTests.py
+++ b/src/engine/SCons/CacheDirTests.py
@@ -249,7 +249,7 @@ class FileTestCase(BaseTestCase):
             warn_caught = 0
             try:
                 f7.push_to_cache()
-            except SCons.Errors.BuildError, e:
+            except SCons.Errors.BuildError as e:
                 assert e.exc_info[0] == SCons.Warnings.CacheWriteErrorWarning
                 warn_caught = 1
             assert warn_caught
diff --git a/src/engine/SCons/Conftest.py b/src/engine/SCons/Conftest.py
index 87a3022..4db7e06 100644
--- a/src/engine/SCons/Conftest.py
+++ b/src/engine/SCons/Conftest.py
@@ -101,7 +101,6 @@ Autoconf-like configuration support; low level implementation of tests.
 #
 
 import re
-from types import IntType
 
 #
 # PUBLIC VARIABLES
@@ -745,7 +744,7 @@ def _Have(context, key, have, comment = None):
         line = "#define %s 1\n" % key_up
     elif have == 0:
         line = "/* #undef %s */\n" % key_up
-    elif isinstance(have, IntType):
+    elif isinstance(have, int):
         line = "#define %s %d\n" % (key_up, have)
     else:
         line = "#define %s %s\n" % (key_up, str(have))
diff --git a/src/engine/SCons/Defaults.py b/src/engine/SCons/Defaults.py
index 37cbc99..f1d5bca 100644
--- a/src/engine/SCons/Defaults.py
+++ b/src/engine/SCons/Defaults.py
@@ -261,7 +261,8 @@ def copy_func(dest, src, symlinks=True):
         else:
             return copy_func(dest, os.path.realpath(src))
     elif os.path.isfile(src):
-        return shutil.copy2(src, dest)
+        shutil.copy2(src, dest)
+        return 0
     else:
         return shutil.copytree(src, dest, symlinks)
 
@@ -298,7 +299,7 @@ def mkdir_func(dest):
     for entry in dest:
         try:
             os.makedirs(str(entry))
-        except os.error, e:
+        except os.error as e:
             p = str(entry)
             if (e.args[0] == errno.EEXIST or
                     (sys.platform=='win32' and e.args[0]==183)) \
@@ -458,7 +459,7 @@ def processDefines(defs):
                 else:
                     l.append(str(d[0]))
             elif SCons.Util.is_Dict(d):
-                for macro,value in d.iteritems():
+                for macro,value in d.items():
                     if value is not None:
                         l.append(str(macro) + '=' + str(value))
                     else:
diff --git a/src/engine/SCons/DefaultsTests.py b/src/engine/SCons/DefaultsTests.py
index 8b9fb4e..141243b 100644
--- a/src/engine/SCons/DefaultsTests.py
+++ b/src/engine/SCons/DefaultsTests.py
@@ -70,7 +70,7 @@ class DefaultsTestCase(unittest.TestCase):
         test.write(file, "test\n")
         try:
             mkdir_func(file)
-        except os.error, e:
+        except os.error as e:
             pass
         else:
             fail("expected os.error")
diff --git a/src/engine/SCons/Environment.py b/src/engine/SCons/Environment.py
index 45b24c5..d979005 100644
--- a/src/engine/SCons/Environment.py
+++ b/src/engine/SCons/Environment.py
@@ -128,7 +128,7 @@ future_reserved_construction_var_names = [
 
 def copy_non_reserved_keywords(dict):
     result = semi_deepcopy(dict)
-    for k in result.keys():
+    for k in list(result.keys()):
         if k in reserved_construction_var_names:
             msg = "Ignoring attempt to set reserved variable `$%s'"
             SCons.Warnings.warn(SCons.Warnings.ReservedVariableWarning, msg % k)
@@ -147,7 +147,7 @@ def _set_future_reserved(env, key, value):
 def _set_BUILDERS(env, key, value):
     try:
         bd = env._dict[key]
-        for k in bd.keys():
+        for k in list(bd.keys()):
             del bd[k]
     except KeyError:
         bd = BuilderDict(kwbd, env)
@@ -396,8 +396,8 @@ class SubstitutionEnvironment(object):
         # gotten better than dict.has_key() in Python 2.5.)
         self._special_set_keys = list(self._special_set.keys())
 
-    def __cmp__(self, other):
-        return cmp(self._dict, other._dict)
+    def __eq__(self, other):
+        return self._dict == other._dict
 
     def __delitem__(self, key):
         special = self._special_del.get(key)
@@ -589,7 +589,7 @@ class SubstitutionEnvironment(object):
         out,err = p.communicate()
         status = p.wait()
         if err:
-            sys.stderr.write(unicode(err))
+            sys.stderr.write(u"" + err)
         if status:
             raise OSError("'%s' exited %d" % (command, status))
         return out
@@ -1131,7 +1131,7 @@ class Base(SubstitutionEnvironment):
         in an Environment.
         """
         kw = copy_non_reserved_keywords(kw)
-        for key, val in kw.items():
+        for key, val in list(kw.items()):
             # It would be easier on the eyes to write this using
             # "continue" statements whenever we finish processing an item,
             # but Python 1.5.2 apparently doesn't let you use "continue"
@@ -1201,7 +1201,7 @@ class Base(SubstitutionEnvironment):
                             update_dict(val)
                         except (AttributeError, TypeError, ValueError):
                             if SCons.Util.is_Dict(val):
-                                for k, v in val.items():
+                                for k, v in list(val.items()):
                                     orig[k] = v
                             else:
                                 orig[val] = None
@@ -1330,7 +1330,7 @@ class Base(SubstitutionEnvironment):
                         elif SCons.Util.is_String(val):
                             val = [(val,)]
                         if delete_existing:
-                            dk = filter(lambda x, val=val: x not in val, dk)
+                            dk = list(filter(lambda x, val=val: x not in val, dk))
                             self._dict[key] = dk + val
                         else:
                             dk = [x for x in dk if x not in val]
@@ -1339,7 +1339,7 @@ class Base(SubstitutionEnvironment):
                         # By elimination, val is not a list.  Since dk is a
                         # list, wrap val in a list first.
                         if delete_existing:
-                            dk = filter(lambda x, val=val: x not in val, dk)
+                            dk = list(filter(lambda x, val=val: x not in val, dk))
                             self._dict[key] = dk + [val]
                         else:
                             if not val in dk:
@@ -1363,7 +1363,7 @@ class Base(SubstitutionEnvironment):
                                 val = [val]
                         elif SCons.Util.is_Dict(val):
                             tmp = []
-                            for i,j in val.iteritems():
+                            for i,j in val.items():
                                 if j is not None:
                                     tmp.append((i,j))
                                 else:
@@ -1659,7 +1659,7 @@ class Base(SubstitutionEnvironment):
                             update_dict(val)
                         except (AttributeError, TypeError, ValueError):
                             if SCons.Util.is_Dict(val):
-                                for k, v in val.items():
+                                for k, v in list(val.items()):
                                     orig[k] = v
                             else:
                                 orig[val] = None
@@ -1771,7 +1771,7 @@ class Base(SubstitutionEnvironment):
         return os.path.join(dir, new_prefix+name+new_suffix)
 
     def SetDefault(self, **kw):
-        for k in kw.keys():
+        for k in list(kw.keys()):
             if k in self._dict:
                 del kw[k]
         self.Replace(**kw)
@@ -2246,7 +2246,7 @@ class Base(SubstitutionEnvironment):
             while (node != node.srcnode()):
               node = node.srcnode()
             return node
-        sources = map( final_source, sources );
+        sources = list(map( final_source, sources ));
         # remove duplicates
         return list(set(sources))
 
@@ -2389,7 +2389,7 @@ def NoSubstitutionProxy(subject):
         def __setattr__(self, name, value):
             return setattr(self.__dict__['__subject'], name, value)
         def executor_to_lvars(self, kwdict):
-            if kwdict.has_key('executor'):
+            if 'executor' in kwdict:
                 kwdict['lvars'] = kwdict['executor'].get_lvars()
                 del kwdict['executor']
             else:
diff --git a/src/engine/SCons/EnvironmentTests.py b/src/engine/SCons/EnvironmentTests.py
index 0567906..4b57763 100644
--- a/src/engine/SCons/EnvironmentTests.py
+++ b/src/engine/SCons/EnvironmentTests.py
@@ -21,6 +21,8 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
+from __future__ import print_function
+
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.compat
@@ -114,11 +116,11 @@ class Scanner(object):
         global scanned_it
         scanned_it[filename] = 1
 
-    def __cmp__(self, other):
+    def __eq__(self, other):
         try:
-            return cmp(self.__dict__, other.__dict__)
+            return self.__dict__ == other.__dict__
         except AttributeError:
-            return 1
+            return False
 
     def get_skeys(self, env):
         return self.skeys
@@ -265,16 +267,10 @@ class SubstitutionTestCase(unittest.TestCase):
         assert isinstance(nodes[0], X)
         assert nodes[0].name == "Util.py UtilTests.py"
 
-        try: unicode
-        except NameError: pass
-        else:
-            code = """if 1:
-                nodes = env.arg2nodes(u"Util.py UtilTests.py", Factory)
-                assert len(nodes) == 1, nodes
-                assert isinstance(nodes[0], X)
-                assert nodes[0].name == u"Util.py UtilTests.py"
-                \n"""
-            exec code in globals(), locals()
+        nodes = env.arg2nodes(u"Util.py UtilTests.py", Factory)
+        assert len(nodes) == 1, nodes
+        assert isinstance(nodes[0], X)
+        assert nodes[0].name == u"Util.py UtilTests.py"
 
         nodes = env.arg2nodes(["Util.py", "UtilTests.py"], Factory)
         assert len(nodes) == 2, nodes
@@ -657,7 +653,7 @@ sys.exit(0)
             cmd = '%s %s' % (python, test.workpath('fail.py'))
             try:
                 env.backtick(cmd)
-            except OSError, e:
+            except OSError as e:
                 assert str(e) == "'%s' exited 1" % cmd, str(e)
             else:
                 self.fail("did not catch expected OSError")
@@ -1566,17 +1562,17 @@ def exists(env):
             env['XXX'] = copy.copy(input)
             try:
                 env.Append(XXX = append)
-            except Exception, e:
-                if failed == 0: print
-                print "    %s Append %s exception: %s" % \
-                      (repr(input), repr(append), e)
+            except Exception as e:
+                if failed == 0: print()
+                print("    %s Append %s exception: %s" % \
+                      (repr(input), repr(append), e))
                 failed = failed + 1
             else:
                 result = env['XXX']
                 if result != expect:
-                    if failed == 0: print
-                    print "    %s Append %s => %s did not match %s" % \
-                          (repr(input), repr(append), repr(result), repr(expect))
+                    if failed == 0: print()
+                    print("    %s Append %s => %s did not match %s" % \
+                          (repr(input), repr(append), repr(result), repr(expect)))
                     failed = failed + 1
             del cases[:3]
         assert failed == 0, "%d Append() cases failed" % failed
@@ -1598,7 +1594,7 @@ def exists(env):
                 self.name = name
             def __str__(self):
                 return self.name
-            def __cmp__(self, other):
+            def __eq__(self, other):
                 raise Exception("should not compare")
 
         ccc = C('ccc')
@@ -1873,7 +1869,7 @@ def generate(env):
         # test for pull request #150
         env = self.TestEnvironment()
         env._dict.pop('BUILDERS')
-        assert env.has_key('BUILDERS') is False
+        assert ('BUILDERS' in env) is False
         env2 = env.Clone()
 
     def test_Copy(self):
@@ -1926,7 +1922,7 @@ def generate(env):
             assert x is None, x
 
             sub2_xxx_exe = test.workpath('sub2', 'xxx.exe')
-            os.chmod(sub2_xxx_exe, 0755)
+            os.chmod(sub2_xxx_exe, 0o755)
 
             env = self.TestEnvironment(ENV = { 'PATH' : [sub1, sub2] })
 
@@ -1934,7 +1930,7 @@ def generate(env):
             assert x == 'xxx.exe', x
 
             sub1_xxx_exe = test.workpath('sub1', 'xxx.exe')
-            os.chmod(sub1_xxx_exe, 0755)
+            os.chmod(sub1_xxx_exe, 0o755)
 
             x = env.Detect('xxx.exe')
             assert x == 'xxx.exe', x
@@ -2252,17 +2248,17 @@ f5: \
             env['XXX'] = copy.copy(input)
             try:
                 env.Prepend(XXX = prepend)
-            except Exception, e:
-                if failed == 0: print
-                print "    %s Prepend %s exception: %s" % \
-                      (repr(input), repr(prepend), e)
+            except Exception as e:
+                if failed == 0: print()
+                print("    %s Prepend %s exception: %s" % \
+                      (repr(input), repr(prepend), e))
                 failed = failed + 1
             else:
                 result = env['XXX']
                 if result != expect:
-                    if failed == 0: print
-                    print "    %s Prepend %s => %s did not match %s" % \
-                          (repr(input), repr(prepend), repr(result), repr(expect))
+                    if failed == 0: print()
+                    print("    %s Prepend %s => %s did not match %s" % \
+                          (repr(input), repr(prepend), repr(result), repr(expect)))
                     failed = failed + 1
             del cases[:3]
         assert failed == 0, "%d Prepend() cases failed" % failed
@@ -2500,10 +2496,10 @@ def generate(env):
         os.mkdir(sub2_xxx_exe)
 
         test.write(sub3_xxx_exe, "\n")
-        os.chmod(sub3_xxx_exe, 0777)
+        os.chmod(sub3_xxx_exe, 0o777)
 
         test.write(sub4_xxx_exe, "\n")
-        os.chmod(sub4_xxx_exe, 0777)
+        os.chmod(sub4_xxx_exe, 0o777)
 
         env_path = os.environ['PATH']
 
diff --git a/src/engine/SCons/Errors.py b/src/engine/SCons/Errors.py
index 3b8c3f9..3cc9c6d 100644
--- a/src/engine/SCons/Errors.py
+++ b/src/engine/SCons/Errors.py
@@ -32,8 +32,6 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
-import exceptions
-
 class BuildError(Exception):
     """ Errors occuring while building.
 
@@ -146,6 +144,7 @@ def convert_to_BuildError(status, exc_info=None):
     if not exc_info and isinstance(status, Exception):
         exc_info = (status.__class__, status, None)
 
+
     if isinstance(status, BuildError):
         buildError = status
         buildError.exitstatus = 2   # always exit with 2 on build errors
@@ -163,14 +162,17 @@ def convert_to_BuildError(status, exc_info=None):
             status=2,
             exitstatus=2,
             exc_info=exc_info)
-    elif isinstance(status, exceptions.EnvironmentError):
+    elif isinstance(status, (EnvironmentError, OSError, IOError)):
         # If an IOError/OSError happens, raise a BuildError.
         # Report the name of the file or directory that caused the
         # error, which might be different from the target being built
         # (for example, failure to create the directory in which the
         # target file will appear).
-        try: filename = status.filename
-        except AttributeError: filename = None
+        try:
+            filename = status.filename
+        except AttributeError:
+            filename = None
+
         buildError = BuildError( 
             errstr=status.strerror,
             status=status.errno,
diff --git a/src/engine/SCons/ErrorsTests.py b/src/engine/SCons/ErrorsTests.py
index d57faa5..c38158d 100644
--- a/src/engine/SCons/ErrorsTests.py
+++ b/src/engine/SCons/ErrorsTests.py
@@ -38,7 +38,7 @@ class ErrorsTestCase(unittest.TestCase):
             raise SCons.Errors.BuildError(
                 errstr = "foo", status=57, filename="file", exc_info=(1,2,3),
                 node = "n", executor="e", action="a", command="c")
-        except SCons.Errors.BuildError, e:
+        except SCons.Errors.BuildError as e:
             assert e.errstr == "foo"
             assert e.status == 57
             assert e.exitstatus == 2, e.exitstatus
@@ -53,7 +53,7 @@ class ErrorsTestCase(unittest.TestCase):
         try:
             raise SCons.Errors.BuildError("n", "foo", 57, 3, "file", 
                                           "e", "a", "c", (1,2,3))
-        except SCons.Errors.BuildError, e:
+        except SCons.Errors.BuildError as e:
             assert e.errstr == "foo", e.errstr
             assert e.status == 57, e.status
             assert e.exitstatus == 3, e.exitstatus
@@ -67,7 +67,7 @@ class ErrorsTestCase(unittest.TestCase):
 
         try:
             raise SCons.Errors.BuildError()
-        except SCons.Errors.BuildError, e:
+        except SCons.Errors.BuildError as e:
             assert e.errstr == "Unknown error"
             assert e.status == 2
             assert e.exitstatus == 2
@@ -83,21 +83,21 @@ class ErrorsTestCase(unittest.TestCase):
         """Test the InternalError exception."""
         try:
             raise SCons.Errors.InternalError("test internal error")
-        except SCons.Errors.InternalError, e:
+        except SCons.Errors.InternalError as e:
             assert e.args == ("test internal error",)
 
     def test_UserError(self):
         """Test the UserError exception."""
         try:
             raise SCons.Errors.UserError("test user error")
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             assert e.args == ("test user error",)
 
     def test_ExplicitExit(self):
         """Test the ExplicitExit exception."""
         try:
             raise SCons.Errors.ExplicitExit("node")
-        except SCons.Errors.ExplicitExit, e:
+        except SCons.Errors.ExplicitExit as e:
             assert e.node == "node"
 
 if __name__ == "__main__":
diff --git a/src/engine/SCons/Executor.py b/src/engine/SCons/Executor.py
index b6d4cb6..7107fde 100644
--- a/src/engine/SCons/Executor.py
+++ b/src/engine/SCons/Executor.py
@@ -455,9 +455,9 @@ class Executor(object):
         except KeyError:
             pass
         env = self.get_build_env()
-        result = "".join([action.get_contents(self.get_all_targets(),
-                                              self.get_all_sources(),
-                                              env)
+        result = b"".join([action.get_contents(self.get_all_targets(),
+                                               self.get_all_sources(),
+                                               env)
                           for action in self.get_action_list()])
         self._memo['get_contents'] = result
         return result
diff --git a/src/engine/SCons/ExecutorTests.py b/src/engine/SCons/ExecutorTests.py
index f390319..99c6226 100644
--- a/src/engine/SCons/ExecutorTests.py
+++ b/src/engine/SCons/ExecutorTests.py
@@ -311,7 +311,7 @@ class ExecutorTestCase(unittest.TestCase):
 
         try:
             r = x.prepare()
-        except SCons.Errors.StopError, e:
+        except SCons.Errors.StopError as e:
             assert str(e) == "Source `s2' not found, needed by target `t1'.", e
         else:
             raise AssertionError("did not catch expected StopError: %s" % r)
diff --git a/src/engine/SCons/Job.py b/src/engine/SCons/Job.py
index 42b009e..c0e80b1 100644
--- a/src/engine/SCons/Job.py
+++ b/src/engine/SCons/Job.py
@@ -278,14 +278,14 @@ else:
 
             try:
                 prev_size = threading.stack_size(stack_size*1024) 
-            except AttributeError, e:
+            except AttributeError as e:
                 # Only print a warning if the stack size has been
                 # explicitly set.
                 if not explicit_stack_size is None:
                     msg = "Setting stack size is unsupported by this version of Python:\n    " + \
                         e.args[0]
                     SCons.Warnings.warn(SCons.Warnings.StackSizeWarning, msg)
-            except ValueError, e:
+            except ValueError as e:
                 msg = "Setting stack size failed:\n    " + str(e)
                 SCons.Warnings.warn(SCons.Warnings.StackSizeWarning, msg)
 
diff --git a/src/engine/SCons/Memoize.py b/src/engine/SCons/Memoize.py
index 5144f83..9774bdd 100644
--- a/src/engine/SCons/Memoize.py
+++ b/src/engine/SCons/Memoize.py
@@ -20,6 +20,7 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -123,13 +124,12 @@ class Counter(object):
     def key(self):
         return self.cls_name+'.'+self.method_name
     def display(self):
-        fmt = "    %7d hits %7d misses    %s()"
-        print fmt % (self.hit, self.miss, self.key())
-    def __cmp__(self, other):
+        print("    {:7d} hits {:7d} misses    {}()".format(self.hit, self.miss, self.key()))
+    def __eq__(self, other):
         try:
-            return cmp(self.key(), other.key())
+            return self.key() == other.key()
         except AttributeError:
-            return 0
+            return True
 
 class CountValue(Counter):
     """
@@ -185,7 +185,7 @@ def Dump(title=None):
         collected so far.
     """
     if title:
-        print title
+        print(title)
     for counter in sorted(CounterList):
         CounterList[counter].display()
 
diff --git a/src/engine/SCons/MemoizeTests.py b/src/engine/SCons/MemoizeTests.py
index 77ff6bc..3ce9a11 100644
--- a/src/engine/SCons/MemoizeTests.py
+++ b/src/engine/SCons/MemoizeTests.py
@@ -34,7 +34,6 @@ import SCons.Memoize
 SCons.Memoize.EnableMemoization()
 
 class FakeObject(object):
-
     def __init__(self):
         self._memo = {}
 
diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index 4a4942b..d19afa9 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -31,6 +31,7 @@ that can be used by scripts or modules looking for the canonical default.
 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -122,7 +123,7 @@ def save_strings(val):
 # tells us whether or not os.path.splitdrive() actually does anything
 # on this system, and therefore whether we need to bother calling it
 # when looking up path names in various methods below.
-# 
+#
 
 do_splitdrive = None
 _my_splitdrive =None
@@ -157,7 +158,7 @@ def initialize_do_splitdrive():
     global OS_SEP
     global UNC_PREFIX
     global os_sep_is_slash
-    
+
     OS_SEP = os.sep
     UNC_PREFIX = OS_SEP + OS_SEP
     os_sep_is_slash = OS_SEP == '/'
@@ -178,7 +179,7 @@ needs_normpath_check = re.compile(
       #    b) The path starts with '..'. E.g. '../' or '../moredirs'
       #       but we not match '..abc/'.
       #    c) The path ends with '..'. E.g. '/..' or 'dirs/..'
-      #    d) The path contains a '..' in the middle. 
+      #    d) The path contains a '..' in the middle.
       #       E.g. dirs/../moredirs
 
       (.*/)?\.\.(?:/|$) |
@@ -200,7 +201,7 @@ needs_normpath_check = re.compile(
 
       \./|.*/\.(?:/|$)
 
-    ''', 
+    ''',
     re.VERBOSE
     )
 needs_normpath_match = needs_normpath_check.match
@@ -564,7 +565,7 @@ class EntryProxy(SCons.Util.Proxy):
         except KeyError:
             try:
                 attr = SCons.Util.Proxy.__getattr__(self, name)
-            except AttributeError, e:
+            except AttributeError as e:
                 # Raise our own AttributeError subclass with an
                 # overridden __str__() method that identifies the
                 # name of the entry that caused the exception.
@@ -670,14 +671,14 @@ class Base(SCons.Node.Node):
             single variables lazily when required, in order to save memory.
             The redirection to the getters lets older Tools and
             SConstruct continue to work without any additional changes,
-            fully transparent to the user. 
+            fully transparent to the user.
             Note, that __getattr__ is only called as fallback when the
             requested attribute can't be found, so there should be no
             speed performance penalty involved for standard builds.
         """
         if attr in node_bwcomp:
             return node_bwcomp[attr](self)
-        
+
         raise AttributeError("%r object has no attribute %r" %
                          (self.__class__, attr))
 
@@ -799,7 +800,7 @@ class Base(SCons.Node.Node):
         path_elems = self.get_path_elements()
         pathname = ''
         try: i = path_elems.index(dir)
-        except ValueError: 
+        except ValueError:
             for p in path_elems[:-1]:
                 pathname += p.dirname
         else:
@@ -840,13 +841,13 @@ class Base(SCons.Node.Node):
             return self.name
         else:
             return self.dir.entry_path(self.name)
-        
+
     def get_tpath(self):
         if self.dir._tpath == '.':
             return self.name
         else:
             return self.dir.entry_tpath(self.name)
-        
+
     def get_path_elements(self):
         return self.dir._path_elements + [self]
 
@@ -939,7 +940,7 @@ class Base(SCons.Node.Node):
 
     def _glob1(self, pattern, ondisk=True, source=False, strings=False):
         return []
-    
+
 # Dict that provides a simple backward compatibility
 # layer for the Node attributes 'abspath', 'labspath',
 # 'path', 'tpath' and 'path_elements'.
@@ -979,7 +980,7 @@ class Entry(Base):
     def __init__(self, name, directory, fs):
         Base.__init__(self, name, directory, fs)
         self._func_exists = 3
-        self._func_get_contents = 1 
+        self._func_get_contents = 1
 
     def diskcheck_match(self):
         pass
@@ -1198,7 +1199,7 @@ class FS(LocalFS):
 
         DirNodeInfo.fs = self
         FileNodeInfo.fs = self
-    
+
     def set_SConstruct_dir(self, dir):
         self.SConstruct_dir = dir
 
@@ -1310,7 +1311,7 @@ class FS(LocalFS):
             p = p.strip('/')
 
             needs_normpath = needs_normpath_match(p)
-            
+
             # The path is relative to the top-level SCons directory.
             if p in ('', '.'):
                 p = directory.get_labspath()
@@ -1469,7 +1470,7 @@ class FS(LocalFS):
         """
         Globs
 
-        This is mainly a shim layer 
+        This is mainly a shim layer
         """
         if cwd is None:
             cwd = self.getcwd()
@@ -1555,7 +1556,7 @@ class Dir(Base):
         self._func_sconsign = 1
         self._func_exists = 2
         self._func_get_contents = 2
-        
+
         self._abspath = SCons.Util.silent_intern(self.dir.entry_abspath(self.name))
         self._labspath = SCons.Util.silent_intern(self.dir.entry_labspath(self.name))
         if self.dir._path == '.':
@@ -1594,7 +1595,7 @@ class Dir(Base):
             # Prepend MkdirBuilder action to existing action list
             l = self.get_executor().action_list
             a = get_MkdirBuilder().action
-            l.insert(0, a) 
+            l.insert(0, a)
             self.get_executor().set_action_list(l)
 
     def diskcheck_match(self):
@@ -1742,7 +1743,7 @@ class Dir(Base):
 
             path_elems = ['..'] * (len(self._path_elements) - i) \
                          + [n.name for n in other._path_elements[i:]]
-             
+
             result = OS_SEP.join(path_elems)
 
         memo_dict[other] = result
@@ -1913,10 +1914,10 @@ class Dir(Base):
 
     def get_internal_path(self):
         return self._path
-        
+
     def get_tpath(self):
         return self._tpath
-        
+
     def get_path_elements(self):
         return self._path_elements
 
@@ -1936,7 +1937,7 @@ class Dir(Base):
         """ Searches through the file/dir entries of the current
             directory, and returns True if a physical entry with the given
             name could be found.
-            
+
             @see rentry_exists_on_disk
         """
         try:
@@ -1970,10 +1971,10 @@ class Dir(Base):
             The local directory (self) gets searched first, so
             repositories take a lower precedence regarding the
             searching order.
-            
+
             @see entry_exists_on_disk
         """
-        
+
         rentry_exists = self.entry_exists_on_disk(name)
         if not rentry_exists:
             # Search through the repository folders
@@ -2256,9 +2257,9 @@ class RootDir(Dir):
     add a separator when creating the path names of entries within
     this directory.
     """
-    
+
     __slots__ = ['_lookupDict']
-    
+
     def __init__(self, drive, fs):
         if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.RootDir')
         SCons.Node.Node.__init__(self)
@@ -2266,7 +2267,7 @@ class RootDir(Dir):
         # Handle all the types of drives:
         if drive == '':
             # No drive, regular UNIX root or Windows default drive.
-            name = OS_SEP 
+            name = OS_SEP
             dirname = OS_SEP
         elif drive == '//':
             # UNC path
@@ -2336,7 +2337,7 @@ class RootDir(Dir):
         self._func_sconsign = 1
         self._func_exists = 2
         self._func_get_contents = 2
-        
+
         # Don't just reset the executor, replace its action list,
         # because it might have some pre-or post-actions that need to
         # be preserved.
@@ -2352,9 +2353,9 @@ class RootDir(Dir):
             # Prepend MkdirBuilder action to existing action list
             l = self.get_executor().action_list
             a = get_MkdirBuilder().action
-            l.insert(0, a) 
+            l.insert(0, a)
             self.get_executor().set_action_list(l)
-      
+
 
     def must_be_same(self, klass):
         if klass is Dir:
@@ -2628,11 +2629,11 @@ class File(Base):
         self.store_info = 1
         self._func_exists = 4
         self._func_get_contents = 3
-        
+
         # Initialize this Node's decider function to decide_source() because
         # every file is a source file until it has a Builder attached...
         self.changed_since_last_build = 4
-        
+
         # If there was already a Builder set on this entry, then
         # we need to make sure we call the target-decider function,
         # not the source-decider.  Reaching in and doing this by hand
@@ -2681,12 +2682,12 @@ class File(Base):
         try:
             cs = SCons.Util.MD5filesignature(fname,
                 chunksize=SCons.Node.FS.File.md5_chunksize*1024)
-        except EnvironmentError, e:
+        except EnvironmentError as e:
             if not e.filename:
                 e.filename = fname
             raise
         return cs
-        
+
     @SCons.Memoize.CountMethodCall
     def get_size(self):
         try:
@@ -2960,11 +2961,11 @@ class File(Base):
     def release_target_info(self):
         """Called just after this node has been marked
          up-to-date or was built completely.
-         
+
          This is where we try to release as many target node infos
          as possible for clean builds and update runs, in order
          to minimize the overall memory consumption.
-         
+
          We'd like to remove a lot more attributes like self.sources
          and self.sources_set, but they might get used
          in a next build step. For example, during configuration
@@ -2972,18 +2973,18 @@ class File(Base):
          which linker to use for the resulting Program (gcc vs. g++)!
          That's why we check for the 'keep_targetinfo' attribute,
          config Nodes and the Interactive mode just don't allow
-         an early release of most variables. 
+         an early release of most variables.
 
          In the same manner, we can't simply remove the self.attributes
          here. The smart linking relies on the shared flag, and some
          parts of the java Tool use it to transport information
          about nodes...
-         
+
          @see: built() and Node.release_target_info()
          """
         if (self.released_target_info or SCons.Node.interactive):
             return
-        
+
         if not hasattr(self.attributes, 'keep_targetinfo'):
             # Cache some required values, before releasing
             # stuff like env, executor and builder...
@@ -3056,7 +3057,7 @@ class File(Base):
     def _rmv_existing(self):
         self.clear_memoized_values()
         if SCons.Node.print_duplicate:
-            print "dup: removing existing target %s"%self
+            print("dup: removing existing target {}".format(self))
         e = Unlink(self, [], None)
         if isinstance(e, SCons.Errors.BuildError):
             raise e
@@ -3080,9 +3081,8 @@ class File(Base):
             else:
                 try:
                     self._createDir()
-                except SCons.Errors.StopError, drive:
-                    desc = "No drive `%s' for target `%s'." % (drive, self)
-                    raise SCons.Errors.StopError(desc)
+                except SCons.Errors.StopError as drive:
+                    raise SCons.Errors.StopError("No drive `{}' for target `{}'.".format(drive, self))
 
     #
     #
@@ -3098,12 +3098,11 @@ class File(Base):
     def do_duplicate(self, src):
         self._createDir()
         if SCons.Node.print_duplicate:
-            print "dup: relinking variant '%s' from '%s'"%(self, src)
+            print("dup: relinking variant '{}' from '{}'".format(self, src))
         Unlink(self, None, None)
         e = Link(self, src, None)
         if isinstance(e, SCons.Errors.BuildError):
-            desc = "Cannot duplicate `%s' in `%s': %s." % (src.get_internal_path(), self.dir._path, e.errstr)
-            raise SCons.Errors.StopError(desc)
+            raise SCons.Errors.StopError("Cannot duplicate `{}' in `{}': {}.".format(src.get_internal_path(), self.dir._path, e.errstr))
         self.linked = 1
         # The Link() action may or may not have actually
         # created the file, depending on whether the -n
@@ -3117,7 +3116,6 @@ class File(Base):
             return self._memo['exists']
         except KeyError:
             pass
-        
         result = SCons.Node._exists_map[self._func_exists](self)
         self._memo['exists'] = result
         return result
@@ -3199,37 +3197,37 @@ class File(Base):
 
     def built(self):
         """Called just after this File node is successfully built.
-        
+
          Just like for 'release_target_info' we try to release
          some more target node attributes in order to minimize the
          overall memory consumption.
-         
+
          @see: release_target_info
         """
 
         SCons.Node.Node.built(self)
 
-        if (not SCons.Node.interactive and 
+        if (not SCons.Node.interactive and
             not hasattr(self.attributes, 'keep_targetinfo')):
-            # Ensure that the build infos get computed and cached...        
+            # Ensure that the build infos get computed and cached...
             SCons.Node.store_info_map[self.store_info](self)
             # ... then release some more variables.
             self._specific_sources = False
             self._labspath = None
             self._save_str()
             self.cwd = None
-             
+
             self.scanner_paths = None
 
     def changed(self, node=None, allowcache=False):
         """
         Returns if the node is up-to-date with respect to the BuildInfo
-        stored last time it was built. 
-        
+        stored last time it was built.
+
         For File nodes this is basically a wrapper around Node.changed(),
         but we allow the return value to get cached after the reference
         to the Executor got released in release_target_info().
-        
+
         @see: Node.changed()
         """
         if node is None:
@@ -3237,7 +3235,7 @@ class File(Base):
                 return self._memo['changed']
             except KeyError:
                 pass
-        
+
         has_changed = SCons.Node.Node.changed(self, node)
         if allowcache:
             self._memo['changed'] = has_changed
@@ -3290,7 +3288,7 @@ class File(Base):
                         # ...and they'd like a local copy.
                         e = LocalCopy(self, r, None)
                         if isinstance(e, SCons.Errors.BuildError):
-                            raise 
+                            raise
                         SCons.Node.store_info_map[self.store_info](self)
                     if T: Trace(' 1\n')
                     return 1
@@ -3372,12 +3370,12 @@ class File(Base):
         It computes and returns the signature for this
         node's contents.
         """
-        
+
         try:
             return self.contentsig
         except AttributeError:
             pass
-        
+
         executor = self.get_executor()
 
         result = self.contentsig = SCons.Util.MD5signature(executor.get_contents())
@@ -3397,7 +3395,7 @@ class File(Base):
             return self.cachesig
         except AttributeError:
             pass
-        
+
         # Collect signatures for all children
         children = self.children()
         sigs = [n.get_cachedir_csig() for n in children]
@@ -3461,7 +3459,7 @@ class FileFinder(object):
 
     def _find_file_key(self, filename, paths, verbose=None):
         return (filename, paths)
-        
+
     @SCons.Memoize.CountDictCall(_find_file_key)
     def find_file(self, filename, paths, verbose=None):
         """
@@ -3547,7 +3545,7 @@ def invalidate_node_memos(targets):
 
     if not SCons.Util.is_List(targets):
         targets = [targets]
-    
+
     for entry in targets:
         # If the target is a Node object, clear the cache. If it is a
         # filename, look up potentially existing Node object first.
@@ -3559,7 +3557,7 @@ def invalidate_node_memos(targets):
             # do not correspond to an existing Node object.
             node = get_default_fs().Entry(entry)
             if node:
-                node.clear_memoized_values()                        
+                node.clear_memoized_values()
 
 # Local Variables:
 # tab-width:4
diff --git a/src/engine/SCons/Node/FSTests.py b/src/engine/SCons/Node/FSTests.py
index fc27859..b9c19bc 100644
--- a/src/engine/SCons/Node/FSTests.py
+++ b/src/engine/SCons/Node/FSTests.py
@@ -20,7 +20,7 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
-from __future__ import division
+from __future__ import division, print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -569,13 +569,13 @@ class VariantDirTestCase(unittest.TestCase):
             dp = dnode.srcnode().get_internal_path()
             expect = os.path.normpath(srcnode_map.get(dir, dir))
             if dp != expect:
-                print "Dir `%s' srcnode() `%s' != expected `%s'" % (dir, dp, expect)
+                print("Dir `%s' srcnode() `%s' != expected `%s'" % (dir, dp, expect))
                 errors = errors + 1
 
             fp = fnode.srcnode().get_internal_path()
             expect = os.path.normpath(srcnode_map.get(f, f))
             if fp != expect:
-                print "File `%s' srcnode() `%s' != expected `%s'" % (f, fp, expect)
+                print("File `%s' srcnode() `%s' != expected `%s'" % (f, fp, expect))
                 errors = errors + 1
 
         for dir in dir_list:
@@ -587,14 +587,14 @@ class VariantDirTestCase(unittest.TestCase):
             tp = t[0].get_internal_path()
             expect = os.path.normpath(alter_map.get(dir, dir))
             if tp != expect:
-                print "Dir `%s' alter_targets() `%s' != expected `%s'" % (dir, tp, expect)
+                print("Dir `%s' alter_targets() `%s' != expected `%s'" % (dir, tp, expect))
                 errors = errors + 1
 
             t, m = fnode.alter_targets()
             tp = t[0].get_internal_path()
             expect = os.path.normpath(alter_map.get(f, f))
             if tp != expect:
-                print "File `%s' alter_targets() `%s' != expected `%s'" % (f, tp, expect)
+                print("File `%s' alter_targets() `%s' != expected `%s'" % (f, tp, expect))
                 errors = errors + 1
 
         self.failIf(errors)
@@ -1084,7 +1084,7 @@ class FSTestCase(_tempdirTestCase):
 
             try:
                 f2 = fs.File(sep.join(['f1', 'f2']), directory = d1)
-            except TypeError, x:
+            except TypeError as x:
                 assert str(x) == ("Tried to lookup File '%s' as a Dir." %
                                   d1_f1), x
             except:
@@ -1092,7 +1092,7 @@ class FSTestCase(_tempdirTestCase):
 
             try:
                 dir = fs.Dir(sep.join(['d1', 'f1']))
-            except TypeError, x:
+            except TypeError as x:
                 assert str(x) == ("Tried to lookup File '%s' as a Dir." %
                                   d1_f1), x
             except:
@@ -1100,7 +1100,7 @@ class FSTestCase(_tempdirTestCase):
 
             try:
                 f2 = fs.File('d1')
-            except TypeError, x:
+            except TypeError as x:
                 assert str(x) == ("Tried to lookup Dir '%s' as a File." %
                                   'd1'), x
             except:
@@ -1641,7 +1641,7 @@ class FSTestCase(_tempdirTestCase):
 
         def unc_workpath(dirs, test=test):
             import ntpath
-            x = apply(test.workpath, dirs)
+            x = test.workpath(*dirs)
             drive, path = ntpath.splitdrive(x)
             unc, path = ntpath.splitunc(path)
             path = strip_slash(path)
@@ -1907,9 +1907,9 @@ class FSTestCase(_tempdirTestCase):
             del cases[:3]
             result = dir.rel_path(other)
             if result != expect:
-                if failed == 0: print
+                if failed == 0: print()
                 fmt = "    dir_path(%(dir)s, %(other)s) => '%(result)s' did not match '%(expect)s'"
-                print fmt % locals()
+                print(fmt % locals())
                 failed = failed + 1
         assert failed == 0, "%d rel_path() cases failed" % failed
 
@@ -2546,9 +2546,9 @@ class GlobTestCase(_tempdirTestCase):
                 fmt = lambda n: n
             if r != result:
                 import pprint
-                print "Glob(%s) expected:" % repr(input)
+                print("Glob(%s) expected:" % repr(input))
                 pprint.pprint(list(map(fmt, result)))
-                print "Glob(%s) got:" % repr(input)
+                print("Glob(%s) got:" % repr(input))
                 pprint.pprint(list(map(fmt, r)))
                 self.fail()
 
@@ -3663,7 +3663,7 @@ class SpecialAttrTestCase(unittest.TestCase):
         caught = None
         try:
             fs.Dir('ddd').get_subst_proxy().no_such_attr
-        except AttributeError, e:
+        except AttributeError as e:
             assert str(e) == "Dir instance 'ddd' has no attribute 'no_such_attr'", e
             caught = 1
         assert caught, "did not catch expected AttributeError"
@@ -3671,7 +3671,7 @@ class SpecialAttrTestCase(unittest.TestCase):
         caught = None
         try:
             fs.Entry('eee').get_subst_proxy().no_such_attr
-        except AttributeError, e:
+        except AttributeError as e:
             # Gets disambiguated to File instance by get_subst_proxy().
             assert str(e) == "File instance 'eee' has no attribute 'no_such_attr'", e
             caught = 1
@@ -3680,7 +3680,7 @@ class SpecialAttrTestCase(unittest.TestCase):
         caught = None
         try:
             fs.File('fff').get_subst_proxy().no_such_attr
-        except AttributeError, e:
+        except AttributeError as e:
             assert str(e) == "File instance 'fff' has no attribute 'no_such_attr'", e
             caught = 1
         assert caught, "did not catch expected AttributeError"
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index 86a5c1d..1a76b60 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -19,6 +19,8 @@ be able to depend on any other type of "thing."
 
 """
 
+from __future__ import print_function
+
 #
 # __COPYRIGHT__
 #
@@ -151,7 +153,7 @@ def exists_file(node):
                     # The source file does not exist.  Make sure no old
                     # copy remains in the variant directory.
                     if print_duplicate:
-                        print "dup: no src for %s, unlinking old variant copy"%self
+                        print("dup: no src for %s, unlinking old variant copy"%self)
                     if exists_base(node) or node.islink():
                         node.fs.unlink(node.get_internal_path())
                     # Return None explicitly because the Base.exists() call
@@ -205,13 +207,13 @@ def get_contents_dir(node):
         contents.append('%s %s\n' % (n.get_csig(), n.name))
     return ''.join(contents)
 
-def get_contents_file(node):    
+def get_contents_file(node):
     if not node.rexists():
         return ''
     fname = node.rfile().get_abspath()
     try:
         contents = open(fname, "rb").read()
-    except EnvironmentError, e:
+    except EnvironmentError as e:
         if not e.filename:
             e.filename = fname
         raise
@@ -407,21 +409,21 @@ class NodeInfoBase(object):
             for name in getattr(obj,'__slots__',()):
                 if hasattr(self, name):
                     state[name] = getattr(self, name)
-    
+
         state['_version_id'] = self.current_version_id
         try:
             del state['__weakref__']
         except KeyError:
             pass
         return state
-    
+
     def __setstate__(self, state):
         """
         Restore the attributes from a pickled state. The version is discarded.
         """
         # TODO check or discard version
         del state['_version_id']
-    
+
         for key, value in state.items():
             if key not in ('__weakref__',):
                 setattr(self, key, value)
@@ -456,7 +458,7 @@ class BuildInfoBase(object):
         """
         state = other.__getstate__()
         self.__setstate__(state)
- 
+
     def __getstate__(self):
         """
         Return all fields that shall be pickled. Walk the slots in the class
@@ -536,7 +538,7 @@ class Node(object):
 
     class Attrs(object):
         __slots__ = ('shared', '__dict__')
- 
+
 
     def __init__(self):
         if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.Node')
@@ -588,7 +590,7 @@ class Node(object):
         self._func_rexists = 1
         self._func_get_contents = 0
         self._func_target_from_source = 0
-        
+
         self.clear_memoized_values()
 
         # Let the interface in which the build engine is embedded
@@ -737,7 +739,7 @@ class Node(object):
         """
         try:
             self.get_executor()(self, **kw)
-        except SCons.Errors.BuildError, e:
+        except SCons.Errors.BuildError as e:
             e.node = self
             raise
 
@@ -776,16 +778,16 @@ class Node(object):
     def release_target_info(self):
         """Called just after this node has been marked
          up-to-date or was built completely.
-         
+
          This is where we try to release as many target node infos
          as possible for clean builds and update runs, in order
          to minimize the overall memory consumption.
-         
+
          By purging attributes that aren't needed any longer after
          a Node (=File) got built, we don't have to care that much how
          many KBytes a Node actually requires...as long as we free
          the memory shortly afterwards.
-         
+
          @see: built() and File.release_target_info()
          """
         pass
@@ -934,7 +936,7 @@ class Node(object):
             node = nodes.pop(0)
 
             scanner = node._get_scanner(env, initial_scanner, root_node_scanner, kw)
-                
+
             if not scanner:
                 continue
 
@@ -958,14 +960,14 @@ class Node(object):
         else:
             # handle explicit scanner case
             scanner = initial_scanner.select(self)
-            
+
         if not scanner:
             # no scanner could be found for the given node's scanner key;
             # thus, make an attempt at using a default.
             scanner = root_node_scanner
-                
+
         return scanner
-        
+
     def get_env_scanner(self, env, kw={}):
         return env.get_scanner(self.scanner_key())
 
@@ -1237,7 +1239,7 @@ class Node(object):
         """Adds dependencies."""
         try:
             self._add_child(self.depends, self.depends_set, depend)
-        except TypeError, e:
+        except TypeError as e:
             e = e.args[0]
             if SCons.Util.is_List(e):
                 s = list(map(str, e))
@@ -1256,7 +1258,7 @@ class Node(object):
         """Adds dependencies to ignore."""
         try:
             self._add_child(self.ignore, self.ignore_set, depend)
-        except TypeError, e:
+        except TypeError as e:
             e = e.args[0]
             if SCons.Util.is_List(e):
                 s = list(map(str, e))
@@ -1270,7 +1272,7 @@ class Node(object):
             return
         try:
             self._add_child(self.sources, self.sources_set, source)
-        except TypeError, e:
+        except TypeError as e:
             e = e.args[0]
             if SCons.Util.is_List(e):
                 s = list(map(str, e))
@@ -1422,14 +1424,14 @@ class Node(object):
         any difference, but we now rely on checking every dependency
         to make sure that any necessary Node information (for example,
         the content signature of an #included .h file) is updated.
-        
+
         The allowcache option was added for supporting the early
         release of the executor/builder structures, right after
         a File target was built. When set to true, the return
         value of this changed method gets cached for File nodes.
         Like this, the executor isn't needed any longer for subsequent
         calls to changed().
-        
+
         @see: FS.File.changed(), FS.File.release_target_info()
         """
         t = 0
diff --git a/src/engine/SCons/Options/__init__.py b/src/engine/SCons/Options/__init__.py
index f6c8483..2544aec 100644
--- a/src/engine/SCons/Options/__init__.py
+++ b/src/engine/SCons/Options/__init__.py
@@ -33,11 +33,11 @@ and will then be removed entirely (some day).
 import SCons.Variables
 import SCons.Warnings
 
-from BoolOption import BoolOption  # okay
-from EnumOption import EnumOption  # okay
-from ListOption import ListOption  # naja
-from PackageOption import PackageOption # naja
-from PathOption import PathOption # okay
+from .BoolOption import BoolOption  # okay
+from .EnumOption import EnumOption  # okay
+from .ListOption import ListOption  # naja
+from .PackageOption import PackageOption # naja
+from .PathOption import PathOption # okay
 
 warned = False
 
diff --git a/src/engine/SCons/Platform/__init__.py b/src/engine/SCons/Platform/__init__.py
index 7f3e90b..7f4639f 100644
--- a/src/engine/SCons/Platform/__init__.py
+++ b/src/engine/SCons/Platform/__init__.py
@@ -21,7 +21,7 @@ their own platform definition.
 
 #
 # __COPYRIGHT__
-# 
+#
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
 # "Software"), to deal in the Software without restriction, including
@@ -41,6 +41,7 @@ their own platform definition.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -130,7 +131,7 @@ class PlatformSpec(object):
 
     def __str__(self):
         return self.name
-        
+
 class TempFileMunge(object):
     """A callable class.  You can set an Environment variable to this,
     then call it with a string argument, then it will perform temporary
@@ -183,9 +184,9 @@ class TempFileMunge(object):
         node = target[0] if SCons.Util.is_List(target) else target
         cmdlist = getattr(node.attributes, 'tempfile_cmdlist', None) \
                     if node is not None else None
-        if cmdlist is not None : 
+        if cmdlist is not None :
             return cmdlist
-        
+
         # We do a normpath because mktemp() has what appears to be
         # a bug in Windows that will use a forward slash as a path
         # delimiter.  Windows's link mistakes that for a command line
@@ -233,14 +234,14 @@ class TempFileMunge(object):
         # purity get in the way of just being helpful, so we'll
         # reach into SCons.Action directly.
         if SCons.Action.print_actions:
-            cmdstr = env.subst(self.cmdstr, SCons.Subst.SUBST_RAW, target, 
+            cmdstr = env.subst(self.cmdstr, SCons.Subst.SUBST_RAW, target,
                                source) if self.cmdstr is not None else ''
             # Print our message only if XXXCOMSTR returns an empty string
             if len(cmdstr) == 0 :
                 print("Using tempfile "+native_tmp+" for command line:\n"+
                       str(cmd[0]) + " " + " ".join(args))
-            
-        # Store the temporary file command list into the target Node.attributes 
+
+        # Store the temporary file command list into the target Node.attributes
         # to avoid creating two temporary files one for print and one for execute.
         cmdlist = [ cmd[0], prefix + native_tmp + '\n' + rm, native_tmp ]
         if node is not None:
@@ -249,7 +250,8 @@ class TempFileMunge(object):
             except AttributeError:
                 pass
         return cmdlist
-    
+
+
 def Platform(name = platform_default()):
     """Select a canned Platform specification.
     """
diff --git a/src/engine/SCons/Platform/aix.py b/src/engine/SCons/Platform/aix.py
index b6933a4..0266dc6 100644
--- a/src/engine/SCons/Platform/aix.py
+++ b/src/engine/SCons/Platform/aix.py
@@ -35,7 +35,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 import os
 import subprocess
 
-import posix
+from . import posix
 
 import SCons.Util
 import SCons.Action
diff --git a/src/engine/SCons/Platform/cygwin.py b/src/engine/SCons/Platform/cygwin.py
index 34c79ff..8b4669c 100644
--- a/src/engine/SCons/Platform/cygwin.py
+++ b/src/engine/SCons/Platform/cygwin.py
@@ -32,7 +32,7 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import posix
+from . import posix
 from SCons.Platform import TempFileMunge
 
 def generate(env):
diff --git a/src/engine/SCons/Platform/darwin.py b/src/engine/SCons/Platform/darwin.py
index 005673b..1cf4aeb 100644
--- a/src/engine/SCons/Platform/darwin.py
+++ b/src/engine/SCons/Platform/darwin.py
@@ -32,7 +32,7 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import posix
+from . import posix
 import os
 
 def generate(env):
diff --git a/src/engine/SCons/Platform/hpux.py b/src/engine/SCons/Platform/hpux.py
index 43d284b..0e0bbcf 100644
--- a/src/engine/SCons/Platform/hpux.py
+++ b/src/engine/SCons/Platform/hpux.py
@@ -32,7 +32,7 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import posix
+from . import posix
 
 def generate(env):
     posix.generate(env)
diff --git a/src/engine/SCons/Platform/irix.py b/src/engine/SCons/Platform/irix.py
index 2baee0b..2e5f217 100644
--- a/src/engine/SCons/Platform/irix.py
+++ b/src/engine/SCons/Platform/irix.py
@@ -32,7 +32,7 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import posix
+from . import posix
 
 def generate(env):
     posix.generate(env)
diff --git a/src/engine/SCons/Platform/os2.py b/src/engine/SCons/Platform/os2.py
index 0fa4553..5ca26bc 100644
--- a/src/engine/SCons/Platform/os2.py
+++ b/src/engine/SCons/Platform/os2.py
@@ -31,7 +31,7 @@ selection method.
 #
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
-import win32
+from . import win32
 
 def generate(env):
     if 'ENV' not in env:
diff --git a/src/engine/SCons/Platform/sunos.py b/src/engine/SCons/Platform/sunos.py
index d23d65c..057fddf 100644
--- a/src/engine/SCons/Platform/sunos.py
+++ b/src/engine/SCons/Platform/sunos.py
@@ -32,7 +32,7 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import posix
+from . import posix
 
 def generate(env):
     posix.generate(env)
diff --git a/src/engine/SCons/Platform/win32.py b/src/engine/SCons/Platform/win32.py
index 4cfabea..269007d 100644
--- a/src/engine/SCons/Platform/win32.py
+++ b/src/engine/SCons/Platform/win32.py
@@ -69,6 +69,7 @@ else:
             win32api.SetHandleInformation(msvcrt.get_osfhandle(self.fileno()),
                 win32con.HANDLE_FLAG_INHERIT, 0)
 
+
     def _scons_open(*args, **kw):
         fp = _builtin_open(*args, **kw)
         win32api.SetHandleInformation(msvcrt.get_osfhandle(fp.fileno()),
@@ -82,7 +83,7 @@ else:
 try:
     import threading
     spawn_lock = threading.Lock()
-    
+
     # This locked version of spawnve works around a Windows
     # MSVCRT bug, because its spawnve is not thread-safe.
     # Without this, python can randomly crash while using -jN.
@@ -111,7 +112,7 @@ except ImportError:
     # simulating a non-existent package.
     def spawnve(mode, file, args, env):
         return os.spawnve(mode, file, args, env)
-    
+
 # The upshot of all this is that, if you are using Python 1.5.2,
 # you had better have cmd or command.com in your PATH when you run
 # scons.
@@ -153,7 +154,7 @@ def piped_spawn(sh, escape, cmd, args, env, stdout, stderr):
         try:
             args = [sh, '/C', escape(' '.join(args)) ]
             ret = spawnve(os.P_WAIT, sh, args, env)
-        except OSError, e:
+        except OSError as e:
             # catch any error
             try:
                 ret = exitvalmap[e[0]]
@@ -181,7 +182,7 @@ def piped_spawn(sh, escape, cmd, args, env, stdout, stderr):
 def exec_spawn(l, env):
     try:
         result = spawnve(os.P_WAIT, l[0], l, env)
-    except OSError, e:
+    except OSError as e:
         try:
             result = exitvalmap[e[0]]
             sys.stderr.write("scons: %s: %s\n" % (l[0], e[1]))
@@ -261,7 +262,7 @@ def get_program_files_dir():
         # A reasonable default if we can't read the registry
         # (Actually, it's pretty reasonable even if we can :-)
         val = os.path.join(os.path.dirname(get_system_root()),"Program Files")
-        
+
     return val
 
 
@@ -346,7 +347,7 @@ def generate(env):
                    os.path.join(systemroot,'System32')
         tmp_pathext = '.com;.exe;.bat;.cmd'
         if 'PATHEXT' in os.environ:
-            tmp_pathext = os.environ['PATHEXT'] 
+            tmp_pathext = os.environ['PATHEXT']
         cmd_interp = SCons.Util.WhereIs('cmd', tmp_path, tmp_pathext)
         if not cmd_interp:
             cmd_interp = SCons.Util.WhereIs('command', tmp_path, tmp_pathext)
@@ -356,7 +357,7 @@ def generate(env):
         if not cmd_interp:
             cmd_interp = env.Detect('command')
 
-    
+
     if 'ENV' not in env:
         env['ENV']        = {}
 
@@ -401,10 +402,10 @@ def generate(env):
     env['TEMPFILEPREFIX'] = '@'
     env['MAXLINELENGTH']  = 2048
     env['ESCAPE']         = escape
-    
+
     env['HOST_OS']        = 'win32'
     env['HOST_ARCH']      = get_architecture().arch
-    
+
 
 # Local Variables:
 # tab-width:4
diff --git a/src/engine/SCons/SConf.py b/src/engine/SCons/SConf.py
index 94027ec..d56b333 100644
--- a/src/engine/SCons/SConf.py
+++ b/src/engine/SCons/SConf.py
@@ -33,6 +33,7 @@ libraries are installed, if some command line options are supported etc.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -134,7 +135,7 @@ def CreateConfigHBuilder(env):
     for k in _ac_config_hs.keys():
         env.SConfigHBuilder(k, env.Value(_ac_config_hs[k]))
 
-    
+
 class SConfWarning(SCons.Warnings.Warning):
     pass
 SCons.Warnings.enableWarningClass(SConfWarning)
@@ -176,7 +177,7 @@ class SConfBuildInfo(SCons.Node.FS.FileBuildInfo):
     contains messages of the original build phase.
     """
     __slots__ = ('result', 'string')
-    
+
     def __init__(self):
         self.result = None # -> 0/None -> no error, != 0 error
         self.string = None # the stdout / stderr output when building the target
@@ -217,7 +218,7 @@ class Streamer(object):
         if self.orig:
             self.orig.flush()
         self.s.flush()
-        
+
 
 class SConfBuildTask(SCons.Taskmaster.AlwaysTask):
     """
@@ -311,7 +312,7 @@ class SConfBuildTask(SCons.Taskmaster.AlwaysTask):
             binfo = self.targets[0].get_stored_info().binfo
             self.display_cached_string(binfo)
             raise SCons.Errors.BuildError # will be 'caught' in self.failed
-        elif is_up_to_date:            
+        elif is_up_to_date:
             self.display("\"%s\" is up to date." % str(self.targets[0]))
             binfo = self.targets[0].get_stored_info().binfo
             self.display_cached_string(binfo)
@@ -332,7 +333,7 @@ class SConfBuildTask(SCons.Taskmaster.AlwaysTask):
                                     env_decider=env.decide_source):
                         env_decider(dependency, target, prev_ni)
                         return True
-                    if env.decide_source.func_code is not force_build.func_code:
+                    if env.decide_source.__code__ is not force_build.__code__:
                         env.Decider(force_build)
                 env['PSTDOUT'] = env['PSTDERR'] = s
                 try:
@@ -346,7 +347,7 @@ class SConfBuildTask(SCons.Taskmaster.AlwaysTask):
             except SystemExit:
                 exc_value = sys.exc_info()[1]
                 raise SCons.Errors.ExplicitExit(self.targets[0],exc_value.code)
-            except Exception, e:
+            except Exception as e:
                 for t in self.targets:
                     binfo = SConfBuildInfo()
                     binfo.merge(t.get_binfo())
@@ -396,7 +397,7 @@ class SConfBase(object):
     """
 
     def __init__(self, env, custom_tests = {}, conf_dir='$CONFIGUREDIR',
-                 log_file='$CONFIGURELOG', config_h = None, _depth = 0): 
+                 log_file='$CONFIGURELOG', config_h = None, _depth = 0):
         """Constructor. Pass additional tests in the custom_tests-dictionary,
         e.g. custom_tests={'CheckPrivate':MyPrivateTest}, where MyPrivateTest
         defines a custom test.
@@ -457,7 +458,7 @@ class SConfBase(object):
 
         If value is None (default), then #define name is written. If value is not
         none, then #define name value is written.
-        
+
         comment is a string which will be put as a C comment in the
         header, to explain the meaning of the value (appropriate C comments /* and
         */ will be put automatically."""
@@ -689,7 +690,7 @@ class SConfBase(object):
         global _ac_config_logs
         global sconf_global
         global SConfFS
-        
+
         self.lastEnvFs = self.env.fs
         self.env.fs = SConfFS
         self._createDir(self.confdir)
@@ -716,7 +717,7 @@ class SConfBase(object):
             self.logstream.write('file %s,line %d:\n\tConfigure(confdir = %s)\n' %
                                  (tb[0], tb[1], str(self.confdir)) )
             SConfFS.chdir(old_fs_dir)
-        else: 
+        else:
             self.logstream = None
         # we use a special builder to create source files from TEXT
         action = SCons.Action.Action(_createSource,
@@ -913,14 +914,14 @@ def CheckType(context, type_name, includes = "", language = None):
 
 def CheckTypeSize(context, type_name, includes = "", language = None, expect = None):
     res = SCons.Conftest.CheckTypeSize(context, type_name,
-                                       header = includes, language = language, 
+                                       header = includes, language = language,
                                        expect = expect)
     context.did_show_result = 1
     return res
 
 def CheckDeclaration(context, declaration, includes = "", language = None):
     res = SCons.Conftest.CheckDeclaration(context, declaration,
-                                          includes = includes, 
+                                          includes = includes,
                                           language = language)
     context.did_show_result = 1
     return not res
@@ -1004,7 +1005,7 @@ def CheckLib(context, library = None, symbol = "main",
 
     if not SCons.Util.is_List(library):
         library = [library]
-    
+
     # ToDo: accept path for the library
     res = SCons.Conftest.CheckLib(context, library, symbol, header = header,
                                         language = language, autoadd = autoadd)
diff --git a/src/engine/SCons/SConfTests.py b/src/engine/SCons/SConfTests.py
index f9ee0d0..15499ed 100644
--- a/src/engine/SCons/SConfTests.py
+++ b/src/engine/SCons/SConfTests.py
@@ -62,7 +62,7 @@ class SConfTestCase(unittest.TestCase):
         # We try to reset scons' state (including all global variables)
         import SCons.SConsign
         SCons.SConsign.write() # simulate normal scons-finish
-        for n in sys.modules.keys():
+        for n in list(sys.modules.keys()):
             if n.split('.')[0] == 'SCons' and n[:12] != 'SCons.compat':
                 m = sys.modules[n]
                 if isinstance(m, ModuleType):
diff --git a/src/engine/SCons/SConsign.py b/src/engine/SCons/SConsign.py
index 74ee804..cb089aa 100644
--- a/src/engine/SCons/SConsign.py
+++ b/src/engine/SCons/SConsign.py
@@ -27,12 +27,13 @@ Writing and reading information to the .sconsign file or files.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
+from __future__ import print_function
+
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.compat
 
 import os
-# compat layer imports "cPickle" for us if it's available.
 import pickle
 
 import SCons.dblite
@@ -84,7 +85,7 @@ def Get_DataBase(dir):
         DB_sync_list.append(db)
         return db, "c"
     except TypeError:
-        print "DataBase =", DataBase
+        print("DataBase =", DataBase)
         raise
 
 def Reset():
@@ -124,16 +125,16 @@ class SConsignEntry(object):
     """
     __slots__ = ("binfo", "ninfo", "__weakref__")
     current_version_id = 2
-    
+
     def __init__(self):
         # Create an object attribute from the class attribute so it ends up
         # in the pickled data in the .sconsign file.
         #_version_id = self.current_version_id
         pass
-    
+
     def convert_to_sconsign(self):
         self.binfo.convert_to_sconsign()
-        
+
     def convert_from_sconsign(self, dir, name):
         self.binfo.convert_from_sconsign(dir, name)
 
@@ -155,7 +156,7 @@ class SConsignEntry(object):
         for key, value in state.items():
             if key not in ('_version_id','__weakref__'):
                 setattr(self, key, value)
-        
+
 class Base(object):
     """
     This is the controlling class for the signatures for the collection of
@@ -239,7 +240,7 @@ class DB(Base):
                     raise TypeError
             except KeyboardInterrupt:
                 raise
-            except Exception, e:
+            except Exception as e:
                 SCons.Warnings.warn(SCons.Warnings.CorruptSConsignWarning,
                                     "Ignoring corrupt sconsign entry : %s (%s)\n"%(self.dir.get_tpath(), e))
             for key, entry in self.entries.items():
@@ -298,7 +299,7 @@ class Dir(Base):
             raise TypeError
 
         if dir:
-            for key, entry in self.entries.items():
+            for key, entry in list(self.entries.items()):
                 entry.convert_from_sconsign(dir, key)
 
 class DirFile(Dir):
@@ -364,7 +365,7 @@ class DirFile(Dir):
         if fname != self.sconsign:
             try:
                 mode = os.stat(self.sconsign)[0]
-                os.chmod(self.sconsign, 0666)
+                os.chmod(self.sconsign, 0o666)
                 os.unlink(self.sconsign)
             except (IOError, OSError):
                 # Try to carry on in the face of either OSError
diff --git a/src/engine/SCons/Scanner/C.py b/src/engine/SCons/Scanner/C.py
index e6ac720..3b34b88 100644
--- a/src/engine/SCons/Scanner/C.py
+++ b/src/engine/SCons/Scanner/C.py
@@ -59,7 +59,7 @@ class SConsCPPScanner(SCons.cpp.PreProcessor):
     def read_file(self, file):
         try:
             fp = open(str(file.rfile()))
-        except EnvironmentError, e:
+        except EnvironmentError as e:
             self.missing.append((file, self.current_file))
             return ''
         else:
diff --git a/src/engine/SCons/Scanner/ProgTests.py b/src/engine/SCons/Scanner/ProgTests.py
index ace3ff4..e7c791c 100644
--- a/src/engine/SCons/Scanner/ProgTests.py
+++ b/src/engine/SCons/Scanner/ProgTests.py
@@ -270,7 +270,7 @@ def suite():
                     assert deps_match(deps, ['d1/l2.lib', 'd1/d2/l3.lib']), map(str, deps)
             suite.addTest(ProgramScannerTestCase4())
             \n"""
-        exec code
+        exec(code)
     return suite
 
 if __name__ == "__main__":
diff --git a/src/engine/SCons/Scanner/ScannerTests.py b/src/engine/SCons/Scanner/ScannerTests.py
index 2496534..e34dcad 100644
--- a/src/engine/SCons/Scanner/ScannerTests.py
+++ b/src/engine/SCons/Scanner/ScannerTests.py
@@ -236,7 +236,7 @@ class BaseTestCase(unittest.TestCase):
     def test___cmp__(self):
         """Test the Scanner.Base class __cmp__() method"""
         s = SCons.Scanner.Base(self.func, "Cmp")
-        assert cmp(s, None)
+        assert s != None
 
     def test_hash(self):
         """Test the Scanner.Base class __hash__() method"""
diff --git a/src/engine/SCons/Scanner/__init__.py b/src/engine/SCons/Scanner/__init__.py
index 562a361..5700fe9 100644
--- a/src/engine/SCons/Scanner/__init__.py
+++ b/src/engine/SCons/Scanner/__init__.py
@@ -221,12 +221,12 @@ class Base(object):
             nodes.append(l)
         return nodes
 
-    def __cmp__(self, other):
+    def __eq__(self, other):
         try:
-            return cmp(self.__dict__, other.__dict__)
+            return self.__dict__ == other.__dict__
         except AttributeError:
             # other probably doesn't have a __dict__
-            return cmp(self.__dict__, other)
+            return self.__dict__ == other
 
     def __hash__(self):
         return id(self)
@@ -324,7 +324,7 @@ class Classic(Current):
 
     def __init__(self, name, suffixes, path_variable, regex, *args, **kw):
 
-        self.cre = re.compile(regex, re.M)
+        self.cre = re.compile(SCons.Util.to_bytes(regex), re.M)
 
         def _scan(node, env, path=(), self=self):
             node = node.rfile()
@@ -393,6 +393,7 @@ class ClassicCPP(Classic):
     the contained filename in group 1.
     """
     def find_include(self, include, source_dir, path):
+        include = list (map (SCons.Util.to_str, include))
         if include[0] == '"':
             paths = (source_dir,) + tuple(path)
         else:
@@ -404,7 +405,7 @@ class ClassicCPP(Classic):
         return n, i
 
     def sort_key(self, include):
-        return SCons.Node.FS._my_normcase(' '.join(include))
+        return SCons.Node.FS._my_normcase(b' '.join(include))
 
 # Local Variables:
 # tab-width:4
diff --git a/src/engine/SCons/Script/Interactive.py b/src/engine/SCons/Script/Interactive.py
index 5450ff5..e7a0658 100644
--- a/src/engine/SCons/Script/Interactive.py
+++ b/src/engine/SCons/Script/Interactive.py
@@ -19,6 +19,7 @@
 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -129,12 +130,12 @@ class SConsInteractiveCmd(cmd.Cmd):
             self.shell_variable = 'SHELL'
 
     def default(self, argv):
-        print "*** Unknown command: %s" % argv[0]
+        print("*** Unknown command: %s" % argv[0])
 
     def onecmd(self, line):
         line = line.strip()
         if not line:
-            print self.lastcmd
+            print(self.lastcmd)
             return self.emptyline()
         self.lastcmd = line
         if line[0] == '!':
@@ -274,7 +275,7 @@ class SConsInteractiveCmd(cmd.Cmd):
         return self.do_build(['build', '--clean'] + argv[1:])
 
     def do_EOF(self, argv):
-        print
+        print()
         self.do_exit(argv)
 
     def _do_one_help(self, arg):
@@ -351,7 +352,7 @@ class SConsInteractiveCmd(cmd.Cmd):
             # Doing the right thing with an argument list currently
             # requires different shell= values on Windows and Linux.
             p = subprocess.Popen(argv, shell=(sys.platform=='win32'))
-        except EnvironmentError, e:
+        except EnvironmentError as e:
             sys.stderr.write('scons: %s: %s\n' % (argv[0], e.strerror))
         else:
             p.wait()
diff --git a/src/engine/SCons/Script/Main.py b/src/engine/SCons/Script/Main.py
index 05c0d75..c0b22a7 100644
--- a/src/engine/SCons/Script/Main.py
+++ b/src/engine/SCons/Script/Main.py
@@ -10,9 +10,13 @@ some other module.  If it's specific to the "scons" script invocation,
 it goes here.
 """
 
+from __future__ import print_function
+
+
 unsupported_python_version = (2, 6, 0)
 deprecated_python_version = (2, 7, 0)
 
+
 # __COPYRIGHT__
 #
 # Permission is hereby granted, free of charge, to any person obtaining
@@ -36,6 +40,7 @@ deprecated_python_version = (2, 7, 0)
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
+
 import SCons.compat
 
 import os
@@ -220,7 +225,7 @@ class BuildTask(SCons.Taskmaster.OutOfDateTask):
                     self.exception_set()
                 self.do_failed()
             else:
-                print "scons: Nothing to be done for `%s'." % t
+                print("scons: Nothing to be done for `%s'." % t)
                 SCons.Taskmaster.OutOfDateTask.executed(self)
         else:
             SCons.Taskmaster.OutOfDateTask.executed(self)
@@ -289,8 +294,8 @@ class BuildTask(SCons.Taskmaster.OutOfDateTask):
             if self.options.debug_includes:
                 tree = t.render_include_tree()
                 if tree:
-                    print
-                    print tree
+                    print()
+                    print(tree)
         SCons.Taskmaster.OutOfDateTask.postprocess(self)
 
     def make_ready(self):
@@ -325,10 +330,10 @@ class CleanTask(SCons.Taskmaster.AlwaysTask):
                 else:
                     errstr = "Path '%s' exists but isn't a file or directory."
                     raise SCons.Errors.UserError(errstr % (pathstr))
-        except SCons.Errors.UserError, e:
-            print e
-        except (IOError, OSError), e:
-            print "scons: Could not remove '%s':" % pathstr, e.strerror
+        except SCons.Errors.UserError as e:
+            print(e)
+        except (IOError, OSError) as e:
+            print("scons: Could not remove '%s':" % pathstr, e.strerror)
 
     def _get_files_to_clean(self):
         result = []
@@ -354,13 +359,13 @@ class CleanTask(SCons.Taskmaster.AlwaysTask):
         for t in self._get_files_to_clean():
             try:
                 removed = t.remove()
-            except OSError, e:
+            except OSError as e:
                 # An OSError may indicate something like a permissions
                 # issue, an IOError would indicate something like
                 # the file not existing.  In either case, print a
                 # message and keep going to try to remove as many
                 # targets as possible.
-                print "scons: Could not remove '%s':" % str(t), e.strerror
+                print("scons: Could not remove '{0}'".format(str(t)), e.strerror)
             else:
                 if removed:
                     display("Removed " + str(t))
@@ -600,7 +605,7 @@ def _scons_internal_error():
     """Handle all errors but user errors. Print out a message telling
     the user what to do in this case and print a normal trace.
     """
-    print 'internal error'
+    print('internal error')
     traceback.print_exc()
     sys.exit(2)
 
@@ -714,7 +719,7 @@ def _load_site_scons_dir(topdir, site_dir_name=None):
                 # the error checking makes it longer.
                 try:
                     m = sys.modules['SCons.Script']
-                except Exception, e:
+                except Exception as e:
                     fmt = 'cannot import site_init.py: missing SCons.Script module %s'
                     raise SCons.Errors.InternalError(fmt % repr(e))
                 try:
@@ -727,10 +732,10 @@ def _load_site_scons_dir(topdir, site_dir_name=None):
                             site_m[k] = m.__dict__[k]
 
                     # This is the magic.
-                    exec fp in site_m
+                    exec(compile(fp.read(), fp.name, 'exec'), site_m)
                 except KeyboardInterrupt:
                     raise
-                except Exception, e:
+                except Exception as e:
                     fmt = '*** Error loading site_init file %s:\n'
                     sys.stderr.write(fmt % repr(site_init_file))
                     raise
@@ -740,7 +745,7 @@ def _load_site_scons_dir(topdir, site_dir_name=None):
                             m.__dict__[k] = site_m[k]
             except KeyboardInterrupt:
                 raise
-            except ImportError, e:
+            except ImportError as e:
                 fmt = '*** cannot import site init file %s:\n'
                 sys.stderr.write(fmt % repr(site_init_file))
                 raise
@@ -792,7 +797,7 @@ def _load_all_site_scons_dirs(topdir, verbose=None):
     dirs=sysdirs + [topdir]
     for d in dirs:
         if verbose:    # this is used by unit tests.
-            print "Loading site dir ", d
+            print("Loading site dir ", d)
         _load_site_scons_dir(d)
 
 def test_load_all_site_scons_dirs(d):
@@ -992,7 +997,7 @@ def _main(parser):
     try:
         for script in scripts:
             SCons.Script._SConscript._SConscript(fs, script)
-    except SCons.Errors.StopError, e:
+    except SCons.Errors.StopError as e:
         # We had problems reading an SConscript file, such as it
         # couldn't be copied in to the VariantDir.  Since we're just
         # reading SConscript files and haven't started building
@@ -1053,8 +1058,8 @@ def _main(parser):
             # SConscript files.  Give them the options usage.
             raise SConsPrintHelpException
         else:
-            print help_text
-            print "Use scons -H for help about command-line options."
+            print(help_text)
+            print("Use scons -H for help about command-line options.")
         exit_status = 0
         return
 
@@ -1091,7 +1096,7 @@ def _main(parser):
         nodes = _build_targets(fs, options, targets, target_top)
         if not nodes:
             revert_io()
-            print 'Found nothing to build'
+            print('Found nothing to build')
             exit_status = 2
 
 def _build_targets(fs, options, targets, target_top):
@@ -1335,7 +1340,7 @@ def main():
     parts.append("__COPYRIGHT__")
     version = ''.join(parts)
 
-    import SConsOptions
+    from . import SConsOptions
     parser = SConsOptions.Parser(version)
     values = SConsOptions.SConsValues(parser.get_default_values())
 
@@ -1346,23 +1351,23 @@ def main():
             _exec_main(parser, values)
         finally:
             revert_io()
-    except SystemExit, s:
+    except SystemExit as s:
         if s:
             exit_status = s
     except KeyboardInterrupt:
         print("scons: Build interrupted.")
         sys.exit(2)
-    except SyntaxError, e:
+    except SyntaxError as e:
         _scons_syntax_error(e)
     except SCons.Errors.InternalError:
         _scons_internal_error()
-    except SCons.Errors.UserError, e:
+    except SCons.Errors.UserError as e:
         _scons_user_error(e)
     except SConsPrintHelpException:
         parser.print_help()
         exit_status = 0
-    except SCons.Errors.BuildError, e:
-        print e
+    except SCons.Errors.BuildError as e:
+        print(e)
         exit_status = e.exitstatus
     except:
         # An exception here is likely a builtin Python exception Python
@@ -1398,10 +1403,10 @@ def main():
             else:
                 ct = last_command_end - first_command_start
         scons_time = total_time - sconscript_time - ct
-        print "Total build time: %f seconds"%total_time
-        print "Total SConscript file execution time: %f seconds"%sconscript_time
-        print "Total SCons execution time: %f seconds"%scons_time
-        print "Total command execution time: %f seconds"%ct
+        print("Total build time: %f seconds"%total_time)
+        print("Total SConscript file execution time: %f seconds"%sconscript_time)
+        print("Total SCons execution time: %f seconds"%scons_time)
+        print("Total command execution time: %f seconds"%ct)
 
     sys.exit(exit_status)
 
diff --git a/src/engine/SCons/Script/SConsOptions.py b/src/engine/SCons/Script/SConsOptions.py
index f56504a..b2f2858 100644
--- a/src/engine/SCons/Script/SConsOptions.py
+++ b/src/engine/SCons/Script/SConsOptions.py
@@ -161,7 +161,7 @@ class SConsValues(optparse.Values):
         elif name == 'diskcheck':
             try:
                 value = diskcheck_convert(value)
-            except ValueError, v:
+            except ValueError as v:
                 raise SCons.Errors.UserError("Not a valid diskcheck value: %s"%v)
             if 'diskcheck' not in self.__dict__:
                 # No --diskcheck= option was specified on the command line.
@@ -663,7 +663,7 @@ def Parser(version):
     def opt_diskcheck(option, opt, value, parser):
         try:
             diskcheck_value = diskcheck_convert(value)
-        except ValueError, e:
+        except ValueError as e:
             raise OptionValueError("`%s' is not a valid diskcheck type" % e)
         setattr(parser.values, option.dest, diskcheck_value)
 
@@ -830,7 +830,7 @@ def Parser(version):
     tree_options = ["all", "derived", "prune", "status"]
 
     def opt_tree(option, opt, value, parser, tree_options=tree_options):
-        import Main
+        from . import Main
         tp = Main.TreePrinter()
         for o in value.split(','):
             if o == 'all':
diff --git a/src/engine/SCons/Script/SConscript.py b/src/engine/SCons/Script/SConscript.py
index e696cfa..6480ace 100644
--- a/src/engine/SCons/Script/SConscript.py
+++ b/src/engine/SCons/Script/SConscript.py
@@ -5,6 +5,8 @@ files.
 
 """
 
+from __future__ import print_function
+
 #
 # __COPYRIGHT__
 #
@@ -26,7 +28,6 @@ files.
 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-from __future__ import division
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -69,7 +70,7 @@ def get_calling_namespaces():
     """Return the locals and globals for the function that called
     into this module in the current call stack."""
     try: 1//0
-    except ZeroDivisionError: 
+    except ZeroDivisionError:
         # Don't start iterating with the current stack-frame to
         # prevent creating reference cycles (f_back is safe).
         frame = sys.exc_info()[2].tb_frame.f_back
@@ -103,7 +104,7 @@ def compute_exports(exports):
                     retval[export] = loc[export]
                 except KeyError:
                     retval[export] = glob[export]
-    except KeyError, x:
+    except KeyError as x:
         raise SCons.Errors.UserError("Export of non-existent variable '%s'"%x)
 
     return retval
@@ -135,7 +136,7 @@ def Return(*vars, **kw):
         for var in fvars:
             for v in var.split():
                 retval.append(call_stack[-1].globals[v])
-    except KeyError, x:
+    except KeyError as x:
         raise SCons.Errors.UserError("Return of non-existent variable '%s'"%x)
 
     if len(retval) == 1:
@@ -164,7 +165,7 @@ def _SConscript(fs, *files, **kw):
         try:
             SCons.Script.sconscript_reading = SCons.Script.sconscript_reading + 1
             if fn == "-":
-                exec sys.stdin in call_stack[-1].globals
+                exec(sys.stdin, call_stack[-1].globals)
             else:
                 if isinstance(fn, SCons.Node.Node):
                     f = fn
@@ -247,7 +248,8 @@ def _SConscript(fs, *files, **kw):
                         pass
                     try:
                         try:
-                            exec _file_ in call_stack[-1].globals
+                            exec(compile(_file_.read(), _file_.name, 'exec'),
+                                 call_stack[-1].globals)
                         except SConscriptReturn:
                             pass
                     finally:
@@ -272,7 +274,7 @@ def _SConscript(fs, *files, **kw):
                 rdir._create()  # Make sure there's a directory there.
                 try:
                     os.chdir(rdir.get_abspath())
-                except OSError, e:
+                except OSError as e:
                     # We still couldn't chdir there, so raise the error,
                     # but only if actions are being executed.
                     #
@@ -462,15 +464,15 @@ class SConsEnvironment(SCons.Environment.Base):
                 scons_ver_string = '%d.%d.%d' % (major, minor, revision)
             else:
                 scons_ver_string = '%d.%d' % (major, minor)
-            print "SCons %s or greater required, but you have SCons %s" % \
-                  (scons_ver_string, SCons.__version__)
+            print("SCons %s or greater required, but you have SCons %s" % \
+                  (scons_ver_string, SCons.__version__))
             sys.exit(2)
 
     def EnsurePythonVersion(self, major, minor):
         """Exit abnormally if the Python version is not late enough."""
         if sys.version_info < (major, minor):
             v = sys.version.split()[0]
-            print "Python %d.%d or greater required, but you have Python %s" %(major,minor,v)
+            print("Python %d.%d or greater required, but you have Python %s" %(major,minor,v))
             sys.exit(2)
 
     def Exit(self, value=0):
@@ -509,7 +511,7 @@ class SConsEnvironment(SCons.Environment.Base):
                             globals[v] = exports[v]
                         else:
                             globals[v] = global_exports[v]
-        except KeyError,x:
+        except KeyError as x:
             raise SCons.Errors.UserError("Import of non-existent variable '%s'"%x)
 
     def SConscript(self, *ls, **kw):
diff --git a/src/engine/SCons/Script/__init__.py b/src/engine/SCons/Script/__init__.py
index be6e5ce..3fa3a48 100644
--- a/src/engine/SCons/Script/__init__.py
+++ b/src/engine/SCons/Script/__init__.py
@@ -41,7 +41,12 @@ start_time = time.time()
 
 import collections
 import os
-import StringIO
+
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
+
 import sys
 
 # Special chicken-and-egg handling of the "--debug=memoizer" flag:
@@ -67,7 +72,7 @@ if "--debug=memoizer" in _args:
     except SCons.Warnings.Warning:
         # Some warning was thrown.  Arrange for it to be displayed
         # or not after warnings are configured.
-        import Main
+        from . import Main
         exc_type, exc_value, tb = sys.exc_info()
         Main.delayed_warnings.append((exc_type, exc_value))
 del _args
@@ -86,7 +91,7 @@ import SCons.Util
 import SCons.Variables
 import SCons.Defaults
 
-import Main
+from . import Main
 
 main                    = Main.main
 
@@ -130,7 +135,7 @@ GetBuildFailures        = Main.GetBuildFailures
 #repositories            = Main.repositories
 
 #
-import SConscript
+from . import SConscript
 _SConscript = SConscript
 
 call_stack              = _SConscript.call_stack
@@ -264,7 +269,7 @@ def HelpFunction(text, append=False):
     global help_text
     if help_text is None:
         if append:
-            s = StringIO.StringIO()
+            s = StringIO()
             PrintHelp(s)  
             help_text = s.getvalue()
             s.close()
@@ -375,7 +380,7 @@ GlobalDefaultBuilders = [
 ]
 
 for name in GlobalDefaultEnvironmentFunctions + GlobalDefaultBuilders:
-    exec "%s = _SConscript.DefaultEnvironmentCall(%s)" % (name, repr(name))
+    exec ("%s = _SConscript.DefaultEnvironmentCall(%s)" % (name, repr(name)))
 del name
 
 # There are a handful of variables that used to live in the
diff --git a/src/engine/SCons/Subst.py b/src/engine/SCons/Subst.py
index 236b08e..3c9b390 100644
--- a/src/engine/SCons/Subst.py
+++ b/src/engine/SCons/Subst.py
@@ -445,7 +445,7 @@ def scons_subst(strSubst, env, mode=SUBST_RAW, target=None, source=None, gvars={
                             s = eval(key, self.gvars, lvars)
                         except KeyboardInterrupt:
                             raise
-                        except Exception, e:
+                        except Exception as e:
                             if e.__class__ in AllowableExceptions:
                                 return ''
                             raise_exception(e, lvars['TARGETS'], s)
@@ -652,7 +652,7 @@ def scons_subst_list(strSubst, env, mode=SUBST_RAW, target=None, source=None, gv
                             s = eval(key, self.gvars, lvars)
                         except KeyboardInterrupt:
                             raise
-                        except Exception, e:
+                        except Exception as e:
                             if e.__class__ in AllowableExceptions:
                                 return
                             raise_exception(e, lvars['TARGETS'], s)
diff --git a/src/engine/SCons/SubstTests.py b/src/engine/SCons/SubstTests.py
index e625cc7..8eda845 100644
--- a/src/engine/SCons/SubstTests.py
+++ b/src/engine/SCons/SubstTests.py
@@ -20,6 +20,7 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -243,14 +244,14 @@ class SubstTestCase(unittest.TestCase):
             expect = convert(expect)
             try:
                 result = function(input, env, **kwargs)
-            except Exception, e:
+            except Exception as e:
                 fmt = "    input %s generated %s (%s)"
-                print fmt % (repr(input), e.__class__.__name__, repr(e))
+                print(fmt % (repr(input), e.__class__.__name__, repr(e)))
                 failed = failed + 1
             else:
                 if result != expect:
-                    if failed == 0: print
-                    print "    input %s => %s did not match %s" % (repr(input), repr(result), repr(expect))
+                    if failed == 0: print()
+                    print("    input %s => %s did not match %s" % (repr(input), repr(result), repr(expect)))
                     failed = failed + 1
             del cases[:2]
         fmt = "%d %s() cases failed"
@@ -462,18 +463,18 @@ class scons_subst_TestCase(SubstTestCase):
             input, eraw, ecmd, esig = subst_cases[:4]
             result = scons_subst(input, env, mode=SUBST_RAW, gvars=gvars)
             if result != eraw:
-                if failed == 0: print
-                print "    input %s => RAW %s did not match %s" % (repr(input), repr(result), repr(eraw))
+                if failed == 0: print()
+                print("    input %s => RAW %s did not match %s" % (repr(input), repr(result), repr(eraw)))
                 failed = failed + 1
             result = scons_subst(input, env, mode=SUBST_CMD, gvars=gvars)
             if result != ecmd:
-                if failed == 0: print
-                print "    input %s => CMD %s did not match %s" % (repr(input), repr(result), repr(ecmd))
+                if failed == 0: print()
+                print("    input %s => CMD %s did not match %s" % (repr(input), repr(result), repr(ecmd)))
                 failed = failed + 1
             result = scons_subst(input, env, mode=SUBST_SIG, gvars=gvars)
             if result != esig:
-                if failed == 0: print
-                print "    input %s => SIG %s did not match %s" % (repr(input), repr(result), repr(esig))
+                if failed == 0: print()
+                print("    input %s => SIG %s did not match %s" % (repr(input), repr(result), repr(esig)))
                 failed = failed + 1
             del subst_cases[:4]
         assert failed == 0, "%d subst() mode cases failed" % failed
@@ -516,7 +517,7 @@ class scons_subst_TestCase(SubstTestCase):
             class Foo(object):
                 pass
             scons_subst('${foo.bar}', env, gvars={'foo':Foo()})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             expect = [
                 "AttributeError `bar' trying to evaluate `${foo.bar}'",
                 "AttributeError `Foo instance has no attribute 'bar'' trying to evaluate `${foo.bar}'",
@@ -532,7 +533,7 @@ class scons_subst_TestCase(SubstTestCase):
         env = DummyEnv(self.loc)
         try:
             scons_subst('$foo.bar.3.0', env)
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             expect = [
                 # Python 2.3, 2.4
                 "SyntaxError `invalid syntax (line 1)' trying to evaluate `$foo.bar.3.0'",
@@ -548,7 +549,7 @@ class scons_subst_TestCase(SubstTestCase):
         env = DummyEnv(self.loc)
         try:
             scons_subst("${NONE[2]}", env, gvars={'NONE':None})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             expect = [
                 # Python 2.3, 2.4
                 "TypeError `unsubscriptable object' trying to evaluate `${NONE[2]}'",
@@ -567,7 +568,7 @@ class scons_subst_TestCase(SubstTestCase):
             def func(a, b, c):
                 pass
             scons_subst("${func(1)}", env, gvars={'func':func})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             expect = [
                 # Python 2.3, 2.4, 2.5
                 "TypeError `func() takes exactly 3 arguments (1 given)' trying to evaluate `${func(1)}'"
@@ -937,18 +938,18 @@ class scons_subst_list_TestCase(SubstTestCase):
             input, eraw, ecmd, esig = subst_list_cases[:4]
             result = scons_subst_list(input, env, mode=SUBST_RAW, gvars=gvars)
             if result != eraw:
-                if failed == 0: print
-                print "    input %s => RAW %s did not match %s" % (repr(input), repr(result), repr(eraw))
+                if failed == 0: print()
+                print("    input %s => RAW %s did not match %s" % (repr(input), repr(result), repr(eraw)))
                 failed = failed + 1
             result = scons_subst_list(input, env, mode=SUBST_CMD, gvars=gvars)
             if result != ecmd:
-                if failed == 0: print
-                print "    input %s => CMD %s did not match %s" % (repr(input), repr(result), repr(ecmd))
+                if failed == 0: print()
+                print("    input %s => CMD %s did not match %s" % (repr(input), repr(result), repr(ecmd)))
                 failed = failed + 1
             result = scons_subst_list(input, env, mode=SUBST_SIG, gvars=gvars)
             if result != esig:
-                if failed == 0: print
-                print "    input %s => SIG %s did not match %s" % (repr(input), repr(result), repr(esig))
+                if failed == 0: print()
+                print("    input %s => SIG %s did not match %s" % (repr(input), repr(result), repr(esig)))
                 failed = failed + 1
             del subst_list_cases[:4]
         assert failed == 0, "%d subst() mode cases failed" % failed
@@ -960,7 +961,7 @@ class scons_subst_list_TestCase(SubstTestCase):
             class Foo(object):
                 pass
             scons_subst_list('${foo.bar}', env, gvars={'foo':Foo()})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             expect = [
                 "AttributeError `bar' trying to evaluate `${foo.bar}'",
                 "AttributeError `Foo instance has no attribute 'bar'' trying to evaluate `${foo.bar}'",
@@ -976,7 +977,7 @@ class scons_subst_list_TestCase(SubstTestCase):
         env = DummyEnv()
         try:
             scons_subst_list('$foo.bar.3.0', env)
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             expect = [
                 "SyntaxError `invalid syntax' trying to evaluate `$foo.bar.3.0'",
                 "SyntaxError `invalid syntax (line 1)' trying to evaluate `$foo.bar.3.0'",
@@ -1084,8 +1085,8 @@ class scons_subst_once_TestCase(unittest.TestCase):
             input, key, expect = cases[:3]
             result = scons_subst_once(input, env, key)
             if result != expect:
-                if failed == 0: print
-                print "    input %s (%s) => %s did not match %s" % (repr(input), repr(key), repr(result), repr(expect))
+                if failed == 0: print()
+                print("    input %s (%s) => %s did not match %s" % (repr(input), repr(key), repr(result), repr(expect)))
                 failed = failed + 1
             del cases[:3]
         assert failed == 0, "%d subst() cases failed" % failed
diff --git a/src/engine/SCons/Taskmaster.py b/src/engine/SCons/Taskmaster.py
index 86cae42..0f4fd21 100644
--- a/src/engine/SCons/Taskmaster.py
+++ b/src/engine/SCons/Taskmaster.py
@@ -20,6 +20,10 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+from __future__ import print_function
+
+import sys
+
 __doc__ = """
 Generic Taskmaster module for the SCons build engine.
 
@@ -107,7 +111,7 @@ fmt = "%(considered)3d "\
 
 def dump_stats():
     for n in sorted(StatsNodes, key=lambda a: str(a)):
-        print (fmt % n.attributes.stats.__dict__) + str(n)
+        print((fmt % n.attributes.stats.__dict__) + str(n))
 
 
 
@@ -191,13 +195,13 @@ class Task(object):
         executor.prepare()
         for t in executor.get_action_targets():
             if print_prepare:
-                print "Preparing target %s..."%t
+                print("Preparing target %s..."%t)
                 for s in t.side_effects:
-                    print "...with side-effect %s..."%s
+                    print("...with side-effect %s..."%s)
             t.prepare()
             for s in t.side_effects:
                 if print_prepare:
-                    print "...Preparing side-effect %s..."%s
+                    print("...Preparing side-effect %s..."%s)
                 s.prepare()
 
     def get_target(self):
@@ -256,7 +260,7 @@ class Task(object):
             raise
         except SCons.Errors.BuildError:
             raise
-        except Exception, e:
+        except Exception as e:
             buildError = SCons.Errors.convert_to_BuildError(e)
             buildError.node = self.targets[0]
             buildError.exc_info = sys.exc_info()
@@ -305,7 +309,7 @@ class Task(object):
                     t.push_to_cache()
                 t.built()
                 t.visited()
-                if (not print_prepare and 
+                if (not print_prepare and
                     (not hasattr(self, 'options') or not self.options.debug_includes)):
                     t.release_target_info()
             else:
@@ -402,7 +406,7 @@ class Task(object):
                 t.disambiguate().make_ready()
                 is_up_to_date = not t.has_builder() or \
                                 (not t.always_build and t.is_up_to_date())
-            except EnvironmentError, e:
+            except EnvironmentError as e:
                 raise SCons.Errors.BuildError(node=t, errstr=e.strerror, filename=e.filename)
 
             if not is_up_to_date:
@@ -423,7 +427,7 @@ class Task(object):
                 # parallel build...)
                 t.visited()
                 t.set_state(NODE_UP_TO_DATE)
-                if (not print_prepare and 
+                if (not print_prepare and
                     (not hasattr(self, 'options') or not self.options.debug_includes)):
                     t.release_target_info()
 
@@ -537,7 +541,14 @@ class Task(object):
         except ValueError:
             exc_type, exc_value = exc
             exc_traceback = None
-        raise exc_type, exc_value, exc_traceback
+
+        if sys.version_info[0] == 2:
+            exec("raise exc_type, exc_value, exc_traceback")
+        else: #  sys.version_info[0] == 3:
+            exec("raise exc_type(exc_value).with_traceback(exc_traceback)")
+
+        # raise e.__class__, e.__class__(e), sys.exc_info()[2]
+
 
 class AlwaysTask(Task):
     def needs_execute(self):
@@ -810,7 +821,7 @@ class Taskmaster(object):
                 self.ready_exc = (SCons.Errors.ExplicitExit, e)
                 if T: T.write(self.trace_message('       SystemExit'))
                 return node
-            except Exception, e:
+            except Exception as e:
                 # We had a problem just trying to figure out the
                 # children (like a child couldn't be linked in to a
                 # VariantDir, or a Scanner threw something).  Arrange to
@@ -943,7 +954,7 @@ class Taskmaster(object):
         executor = node.get_executor()
         if executor is None:
             return None
-        
+
         tlist = executor.get_all_targets()
 
         task = self.tasker(self, tlist, node in self.original_top, node)
diff --git a/src/engine/SCons/TaskmasterTests.py b/src/engine/SCons/TaskmasterTests.py
index 1d81992..e795f5c 100644
--- a/src/engine/SCons/TaskmasterTests.py
+++ b/src/engine/SCons/TaskmasterTests.py
@@ -697,7 +697,7 @@ class TaskmasterTestCase(unittest.TestCase):
         tm = SCons.Taskmaster.Taskmaster([n3])
         try:
             t = tm.next_task()
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             assert str(e) == "Dependency cycle: n3 -> n1 -> n2 -> n3", str(e)
         else:
             assert 'Did not catch expected UserError'
@@ -851,7 +851,7 @@ class TaskmasterTestCase(unittest.TestCase):
         exc_caught = None
         try:
             t.prepare()
-        except MyException, e:
+        except MyException as e:
             exc_caught = 1
         except:
             pass
@@ -904,7 +904,7 @@ class TaskmasterTestCase(unittest.TestCase):
         t = tm.next_task()
         try:
             t.prepare()
-        except Exception, e:
+        except Exception as e:
             assert str(e) == "Executor.prepare() exception", e
         else:
             raise AssertionError("did not catch expected exception")
@@ -958,7 +958,7 @@ class TaskmasterTestCase(unittest.TestCase):
         t = tm.next_task()
         try:
             t.execute()
-        except SCons.Errors.BuildError, e:
+        except SCons.Errors.BuildError as e:
             assert e.node == n4, e.node
             assert e.errstr == "OtherError : ", e.errstr
             assert len(e.exc_info) == 3, e.exc_info
diff --git a/src/engine/SCons/Tool/386asm.py b/src/engine/SCons/Tool/386asm.py
index 8acc55f..51738eb 100644
--- a/src/engine/SCons/Tool/386asm.py
+++ b/src/engine/SCons/Tool/386asm.py
@@ -37,7 +37,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 from SCons.Tool.PharLapCommon import addPharLapPaths
 import SCons.Util
 
-as_module = __import__('as', globals(), locals(), [])
+as_module = __import__('as', globals(), locals(), [], 1)
 
 def generate(env):
     """Add Builders and construction variables for ar to an Environment."""
diff --git a/src/engine/SCons/Tool/FortranCommon.py b/src/engine/SCons/Tool/FortranCommon.py
index 2df2a32..e450730 100644
--- a/src/engine/SCons/Tool/FortranCommon.py
+++ b/src/engine/SCons/Tool/FortranCommon.py
@@ -26,6 +26,7 @@ Stuff for processing Fortran, common to all fortran dialects.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -61,7 +62,7 @@ def isfortran(env, source):
 def _fortranEmitter(target, source, env):
     node = source[0].rfile()
     if not node.exists() and not node.is_derived():
-       print "Could not locate " + str(node.name)
+       print("Could not locate " + str(node.name))
        return ([], [])
     mod_regex = """(?i)^\s*MODULE\s+(?!PROCEDURE)(\w+)"""
     cre = re.compile(mod_regex,re.M)
@@ -167,7 +168,7 @@ def add_fortran_to_env(env):
     except KeyError:
         FortranSuffixes = ['.f', '.for', '.ftn']
 
-    #print "Adding %s to fortran suffixes" % FortranSuffixes
+    #print("Adding %s to fortran suffixes" % FortranSuffixes)
     try:
         FortranPPSuffixes = env['FORTRANPPFILESUFFIXES']
     except KeyError:
@@ -191,7 +192,7 @@ def add_f77_to_env(env):
     except KeyError:
         F77Suffixes = ['.f77']
 
-    #print "Adding %s to f77 suffixes" % F77Suffixes
+    #print("Adding %s to f77 suffixes" % F77Suffixes)
     try:
         F77PPSuffixes = env['F77PPFILESUFFIXES']
     except KeyError:
diff --git a/src/engine/SCons/Tool/GettextCommon.py b/src/engine/SCons/Tool/GettextCommon.py
index f01371a..e23a2d7 100644
--- a/src/engine/SCons/Tool/GettextCommon.py
+++ b/src/engine/SCons/Tool/GettextCommon.py
@@ -196,7 +196,7 @@ class _POFileBuilder(BuilderBase):
     import SCons.Util
     import SCons.Node
     linguas_files = None
-    if env.has_key('LINGUAS_FILE') and env['LINGUAS_FILE']:
+    if 'LINGUAS_FILE' in env and env['LINGUAS_FILE']:
       linguas_files = env['LINGUAS_FILE']
       # This prevents endless recursion loop (we'll be invoked once for 
       # each target appended here, we must not extend the list again).
@@ -324,7 +324,7 @@ class RPaths(object):
 def _init_po_files(target, source, env):
   """ Action function for `POInit` builder. """
   nop = lambda target, source, env : 0
-  if env.has_key('POAUTOINIT'):
+  if 'POAUTOINIT' in env:
     autoinit = env['POAUTOINIT']
   else:
     autoinit = False
@@ -348,7 +348,7 @@ def _init_po_files(target, source, env):
 #############################################################################
 def _detect_xgettext(env):
   """ Detects *xgettext(1)* binary """
-  if env.has_key('XGETTEXT'):
+  if 'XGETTEXT' in env:
     return env['XGETTEXT']
   xgettext = env.Detect('xgettext');
   if xgettext:
@@ -363,7 +363,7 @@ def _xgettext_exists(env):
 #############################################################################
 def _detect_msginit(env):
   """ Detects *msginit(1)* program. """
-  if env.has_key('MSGINIT'):
+  if 'MSGINIT' in env:
     return env['MSGINIT']
   msginit = env.Detect('msginit');
   if msginit:
@@ -378,7 +378,7 @@ def _msginit_exists(env):
 #############################################################################
 def _detect_msgmerge(env):
   """ Detects *msgmerge(1)* program. """
-  if env.has_key('MSGMERGE'):
+  if 'MSGMERGE' in env:
     return env['MSGMERGE']
   msgmerge = env.Detect('msgmerge');
   if msgmerge:
@@ -393,7 +393,7 @@ def _msgmerge_exists(env):
 #############################################################################
 def _detect_msgfmt(env):
   """ Detects *msgmfmt(1)* program. """
-  if env.has_key('MSGFMT'):
+  if 'MSGFMT' in env:
     return env['MSGFMT']
   msgfmt = env.Detect('msgfmt');
   if msgfmt:
diff --git a/src/engine/SCons/Tool/MSCommon/common.py b/src/engine/SCons/Tool/MSCommon/common.py
index be890e2..bcfee2b 100644
--- a/src/engine/SCons/Tool/MSCommon/common.py
+++ b/src/engine/SCons/Tool/MSCommon/common.py
@@ -20,6 +20,7 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -38,7 +39,7 @@ import SCons.Util
 logfile = os.environ.get('SCONS_MSCOMMON_DEBUG')
 if logfile == '-':
     def debug(x):
-        print x
+        print(x)
 elif logfile:
     try:
         import logging
@@ -114,11 +115,11 @@ def normalize_env(env, keys, force=False):
     normenv = {}
     if env:
         for k in env.keys():
-            normenv[k] = copy.deepcopy(env[k]).encode('mbcs')
+            normenv[k] = copy.deepcopy(env[k])
 
         for k in keys:
             if k in os.environ and (force or not k in normenv):
-                normenv[k] = os.environ[k].encode('mbcs')
+                normenv[k] = os.environ[k]
 
     # This shouldn't be necessary, since the default environment should include system32,
     # but keep this here to be safe, since it's needed to find reg.exe which the MSVC
@@ -211,7 +212,6 @@ def parse_output(output, keep = ("INCLUDE", "LIB", "LIBPATH", "PATH")):
         for p in plist:
             # Do not add empty paths (when a var ends with ;)
             if p:
-                p = p.encode('mbcs')
                 # XXX: For some reason, VC98 .bat file adds "" around the PATH
                 # values, and it screws up the environment later, so we strip
                 # it.
diff --git a/src/engine/SCons/Tool/MSCommon/netframework.py b/src/engine/SCons/Tool/MSCommon/netframework.py
index 8fa3c43..787d008 100644
--- a/src/engine/SCons/Tool/MSCommon/netframework.py
+++ b/src/engine/SCons/Tool/MSCommon/netframework.py
@@ -29,7 +29,7 @@ import os
 import re
 import SCons.Util
 
-from common import read_reg, debug
+from .common import read_reg, debug
 
 # Original value recorded by dcournapeau
 _FRAMEWORKDIR_HKEY_ROOT = r'Software\Microsoft\.NETFramework\InstallRoot'
@@ -40,13 +40,13 @@ def find_framework_root():
     # XXX: find it from environment (FrameworkDir)
     try:
         froot = read_reg(_FRAMEWORKDIR_HKEY_ROOT)
-        debug("Found framework install root in registry: %s" % froot)
-    except SCons.Util.WinError, e:
-        debug("Could not read reg key %s" % _FRAMEWORKDIR_HKEY_ROOT)
+        debug("Found framework install root in registry: {}".format(froot))
+    except SCons.Util.WinError as e:
+        debug("Could not read reg key {}".format(_FRAMEWORKDIR_HKEY_ROOT))
         return None
 
     if not os.path.exists(froot):
-        debug("%s not found on fs" % froot)
+        debug("{} not found on fs".format(froot))
         return None
 
     return froot
diff --git a/src/engine/SCons/Tool/MSCommon/sdk.py b/src/engine/SCons/Tool/MSCommon/sdk.py
index b8b71a6..1845599 100644
--- a/src/engine/SCons/Tool/MSCommon/sdk.py
+++ b/src/engine/SCons/Tool/MSCommon/sdk.py
@@ -33,7 +33,7 @@ import os
 import SCons.Errors
 import SCons.Util
 
-import common
+from . import common
 
 debug = common.debug
 
@@ -76,23 +76,23 @@ class SDKDefinition(object):
             return None
 
         hkey = self.HKEY_FMT % self.hkey_data
-        debug('find_sdk_dir(): checking registry:%s'%hkey)
+        debug('find_sdk_dir(): checking registry:{}'.format(hkey))
 
         try:
             sdk_dir = common.read_reg(hkey)
-        except SCons.Util.WinError, e:
-            debug('find_sdk_dir(): no SDK registry key %s' % repr(hkey))
+        except SCons.Util.WinError as e:
+            debug('find_sdk_dir(): no SDK registry key {}'.format(repr(hkey)))
             return None
 
-        debug('find_sdk_dir(): Trying SDK Dir: %s'%sdk_dir)
+        debug('find_sdk_dir(): Trying SDK Dir: {}'.format(sdk_dir))
 
         if not os.path.exists(sdk_dir):
-            debug('find_sdk_dir():  %s not on file system' % sdk_dir)
+            debug('find_sdk_dir():  {} not on file system'.format(sdk_dir))
             return None
 
         ftc = os.path.join(sdk_dir, self.sanity_check_file)
         if not os.path.exists(ftc):
-            debug("find_sdk_dir(): sanity check %s not found" % ftc)
+            debug("find_sdk_dir(): sanity check {} not found".format(ftc))
             return None
 
         return sdk_dir
@@ -105,7 +105,7 @@ class SDKDefinition(object):
             sdk_dir = self.find_sdk_dir()
             self._sdk_dir = sdk_dir
             return sdk_dir
-        
+
     def get_sdk_vc_script(self,host_arch, target_arch):
         """ Return the script to initialize the VC compiler installed by SDK
         """
@@ -113,11 +113,11 @@ class SDKDefinition(object):
         if (host_arch == 'amd64' and target_arch == 'x86'):
             # No cross tools needed compiling 32 bits on 64 bit machine
             host_arch=target_arch
-        
+
         arch_string=target_arch
         if (host_arch != target_arch):
             arch_string='%s_%s'%(host_arch,target_arch)
-            
+
         debug("sdk.py: get_sdk_vc_script():arch_string:%s host_arch:%s target_arch:%s"%(arch_string,
                                                            host_arch,
                                                            target_arch))
@@ -308,8 +308,7 @@ def set_sdk_by_directory(env, sdk_dir):
 
 def get_sdk_by_version(mssdk):
     if mssdk not in SupportedSDKMap:
-        msg = "SDK version %s is not supported" % repr(mssdk)
-        raise SCons.Errors.UserError(msg)
+        raise SCons.Errors.UserError("SDK version {} is not supported".format(repr(mssdk)))
     get_installed_sdks()
     return InstalledSDKMap.get(mssdk)
 
@@ -327,16 +326,16 @@ def mssdk_setup_env(env):
         if sdk_dir is None:
             return
         sdk_dir = env.subst(sdk_dir)
-        debug('sdk.py:mssdk_setup_env: Using MSSDK_DIR:%s'%sdk_dir)
+        debug('sdk.py:mssdk_setup_env: Using MSSDK_DIR:{}'.format(sdk_dir))
     elif 'MSSDK_VERSION' in env:
         sdk_version = env['MSSDK_VERSION']
         if sdk_version is None:
-            msg = "SDK version is specified as None"  
+            msg = "SDK version is specified as None"
             raise SCons.Errors.UserError(msg)
         sdk_version = env.subst(sdk_version)
         mssdk = get_sdk_by_version(sdk_version)
         if mssdk is None:
-            msg = "SDK version %s is not installed" % sdk_version 
+            msg = "SDK version %s is not installed" % sdk_version
             raise SCons.Errors.UserError(msg)
         sdk_dir = mssdk.get_sdk_dir()
         debug('sdk.py:mssdk_setup_env: Using MSSDK_VERSION:%s'%sdk_dir)
@@ -347,7 +346,7 @@ def mssdk_setup_env(env):
             debug('sdk.py:mssdk_setup_env thinks msvs_version is None')
             return
         msvs_version = env.subst(msvs_version)
-        import vs
+        from . import vs
         msvs = vs.get_vs_by_version(msvs_version)
         debug('sdk.py:mssdk_setup_env:msvs is :%s'%msvs)
         if not msvs:
diff --git a/src/engine/SCons/Tool/MSCommon/vc.py b/src/engine/SCons/Tool/MSCommon/vc.py
index 97e2ffc..f96b8ca 100644
--- a/src/engine/SCons/Tool/MSCommon/vc.py
+++ b/src/engine/SCons/Tool/MSCommon/vc.py
@@ -43,11 +43,11 @@ from string import digits as string_digits
 
 import SCons.Warnings
 
-import common
+from . import common
 
 debug = common.debug
 
-import sdk
+from . import sdk
 
 get_installed_sdks = sdk.get_installed_sdks
 
@@ -108,7 +108,7 @@ def get_host_target(env):
         # PROCESSOR_ARCHITECTURE.
         if not host_platform:
             host_platform = os.environ.get('PROCESSOR_ARCHITECTURE', '')
-            
+
     # Retain user requested TARGET_ARCH
     req_target_platform = env.get('TARGET_ARCH')
     debug('vc.py:get_host_target() req_target_platform:%s'%req_target_platform)
@@ -118,17 +118,17 @@ def get_host_target(env):
         target_platform = req_target_platform
     else:
         target_platform = host_platform
-        
+
     try:
         host = _ARCH_TO_CANONICAL[host_platform.lower()]
-    except KeyError, e:
+    except KeyError as e:
         msg = "Unrecognized host architecture %s"
         raise ValueError(msg % repr(host_platform))
 
     try:
         target = _ARCH_TO_CANONICAL[target_platform.lower()]
-    except KeyError, e:
-        all_archs = str(_ARCH_TO_CANONICAL.keys())
+    except KeyError as e:
+        all_archs = str(list(_ARCH_TO_CANONICAL.keys()))
         raise ValueError("Unrecognized target architecture %s\n\tValid architectures: %s" % (target_platform, all_archs))
 
     return (host, target,req_target_platform)
@@ -183,7 +183,7 @@ _VCVER_TO_PRODUCT_DIR = {
         (SCons.Util.HKEY_LOCAL_MACHINE, r'Microsoft\VisualStudio\6.0\Setup\Microsoft Visual C++\ProductDir'),
         ]
 }
-        
+
 def msvc_version_to_maj_min(msvc_version):
    msvc_version_numeric = ''.join([x for  x in msvc_version if x in string_digits + '.'])
 
@@ -194,7 +194,7 @@ def msvc_version_to_maj_min(msvc_version):
        maj = int(t[0])
        min = int(t[1])
        return maj, min
-   except ValueError, e:
+   except ValueError as e:
        raise ValueError("Unrecognized version %s (%s)" % (msvc_version,msvc_version_numeric))
 
 def is_host_target_supported(host_target, msvc_version):
@@ -244,22 +244,21 @@ def find_vc_pdir(msvc_version):
                 try:
                     # ordinally at win64, try Wow6432Node first.
                     comps = common.read_reg(root + 'Wow6432Node\\' + key, hkroot)
-                except SCons.Util.WinError, e:
+                except SCons.Util.WinError as e:
                     # at Microsoft Visual Studio for Python 2.7, value is not in Wow6432Node
                     pass
             if not comps:
                 # not Win64, or Microsoft Visual Studio for Python 2.7
                 comps = common.read_reg(root + key, hkroot)
-        except SCons.Util.WinError, e:
-            debug('find_vc_dir(): no VC registry key %s' % repr(key))
+        except SCons.Util.WinError as e:
+            debug('find_vc_dir(): no VC registry key {}'.format(repr(key)))
         else:
-            debug('find_vc_dir(): found VC in registry: %s' % comps)
+            debug('find_vc_dir(): found VC in registry: {}'.format(comps))
             if os.path.exists(comps):
                 return comps
             else:
-                debug('find_vc_dir(): reg says dir is %s, but it does not exist. (ignoring)'\
-                          % comps)
-                raise MissingConfiguration("registry dir %s not found on the filesystem" % comps)
+                debug('find_vc_dir(): reg says dir is {}, but it does not exist. (ignoring)'.format(comps))
+                raise MissingConfiguration("registry dir {} not found on the filesystem".format(comps))
     return None
 
 def find_batch_file(env,msvc_version,host_arch,target_arch):
@@ -270,8 +269,8 @@ def find_batch_file(env,msvc_version,host_arch,target_arch):
     pdir = find_vc_pdir(msvc_version)
     if pdir is None:
         raise NoVersionFound("No version of Visual Studio found")
-        
-    debug('vc.py: find_batch_file() pdir:%s'%pdir)
+
+    debug('vc.py: find_batch_file() pdir:{}'.format(pdir))
 
     # filter out e.g. "Exp" from the version name
     msvc_ver_numeric = ''.join([x for x in msvc_version if x in string_digits + "."])
@@ -288,7 +287,7 @@ def find_batch_file(env,msvc_version,host_arch,target_arch):
     if not os.path.exists(batfilename):
         debug("Not found: %s" % batfilename)
         batfilename = None
-    
+
     installed_sdks=get_installed_sdks()
     for _sdk in installed_sdks:
         sdk_bat_file = _sdk.get_sdk_vc_script(host_arch,target_arch)
@@ -296,7 +295,7 @@ def find_batch_file(env,msvc_version,host_arch,target_arch):
             debug("vc.py:find_batch_file() not found:%s"%_sdk)
         else:
             sdk_bat_file_path = os.path.join(pdir,sdk_bat_file)
-            if os.path.exists(sdk_bat_file_path): 
+            if os.path.exists(sdk_bat_file_path):
                 debug('vc.py:find_batch_file() sdk_bat_file_path:%s'%sdk_bat_file_path)
                 return (batfilename,sdk_bat_file_path)
     return (batfilename,None)
@@ -323,7 +322,7 @@ def get_installed_vcs():
                 installed_versions.append(ver)
             else:
                 debug('find_vc_pdir return None for ver %s' % ver)
-        except VisualCException, e:
+        except VisualCException as e:
             debug('did not find VC %s: caught exception %s' % (ver, str(e)))
     return installed_versions
 
@@ -359,7 +358,7 @@ def get_default_version(env):
 
     msvc_version = env.get('MSVC_VERSION')
     msvs_version = env.get('MSVS_VERSION')
-    
+
     debug('get_default_version(): msvc_version:%s msvs_version:%s'%(msvc_version,msvs_version))
 
     if msvs_version and not msvc_version:
@@ -409,7 +408,7 @@ def msvc_find_valid_batch_script(env,version):
     try_target_archs = [target_platform]
     debug("msvs_find_valid_batch_script(): req_target_platform %s target_platform:%s"%(req_target_platform,target_platform))
 
-    # VS2012 has a "cross compile" environment to build 64 bit 
+    # VS2012 has a "cross compile" environment to build 64 bit
     # with x86_amd64 as the argument to the batch setup script
     if req_target_platform in ('amd64','x86_64'):
         try_target_archs.append('x86_amd64')
@@ -427,7 +426,7 @@ def msvc_find_valid_batch_script(env,version):
     for tp in try_target_archs:
         # Set to current arch.
         env['TARGET_ARCH']=tp
-        
+
         debug("vc.py:msvc_find_valid_batch_script() trying target_platform:%s"%tp)
         host_target = (host_platform, tp)
         if not is_host_target_supported(host_target, version):
@@ -435,12 +434,12 @@ def msvc_find_valid_batch_script(env,version):
                 (host_target, version)
             SCons.Warnings.warn(SCons.Warnings.VisualCMissingWarning, warn_msg)
         arg = _HOST_TARGET_ARCH_TO_BAT_ARCH[host_target]
-        
+
         # Try to locate a batch file for this host/target platform combo
         try:
             (vc_script,sdk_script) = find_batch_file(env,version,host_platform,tp)
             debug('vc.py:msvc_find_valid_batch_script() vc_script:%s sdk_script:%s'%(vc_script,sdk_script))
-        except VisualCException, e:
+        except VisualCException as e:
             msg = str(e)
             debug('Caught exception while looking for batch file (%s)' % msg)
             warn_msg = "VC version %s not installed.  " + \
@@ -449,13 +448,13 @@ def msvc_find_valid_batch_script(env,version):
             warn_msg = warn_msg % (version, cached_get_installed_vcs())
             SCons.Warnings.warn(SCons.Warnings.VisualCMissingWarning, warn_msg)
             continue
-        
+
         # Try to use the located batch file for this host/target platform combo
         debug('vc.py:msvc_find_valid_batch_script() use_script 2 %s, args:%s\n' % (repr(vc_script), arg))
         if vc_script:
             try:
                 d = script_env(vc_script, args=arg)
-            except BatchFileExecutionError, e:
+            except BatchFileExecutionError as e:
                 debug('vc.py:msvc_find_valid_batch_script() use_script 3: failed running VC script %s: %s: Error:%s'%(repr(vc_script),arg,e))
                 vc_script=None
                 continue
@@ -463,23 +462,23 @@ def msvc_find_valid_batch_script(env,version):
             debug('vc.py:msvc_find_valid_batch_script() use_script 4: trying sdk script: %s'%(sdk_script))
             try:
                 d = script_env(sdk_script)
-            except BatchFileExecutionError,e:
+            except BatchFileExecutionError as e:
                 debug('vc.py:msvc_find_valid_batch_script() use_script 5: failed running SDK script %s: Error:%s'%(repr(sdk_script),e))
                 continue
         elif not vc_script and not sdk_script:
             debug('vc.py:msvc_find_valid_batch_script() use_script 6: Neither VC script nor SDK script found')
             continue
-        
+
         debug("vc.py:msvc_find_valid_batch_script() Found a working script/target: %s %s"%(repr(sdk_script),arg))
         break # We've found a working target_platform, so stop looking
-    
+
     # If we cannot find a viable installed compiler, reset the TARGET_ARCH
     # To it's initial value
     if not d:
         env['TARGET_ARCH']=req_target_platform
-    
+
     return d
-    
+
 
 def msvc_setup_env(env):
     debug('msvc_setup_env()')
@@ -498,12 +497,12 @@ def msvc_setup_env(env):
     env['MSVS_VERSION'] = version
     env['MSVS'] = {}
 
-    
+
     use_script = env.get('MSVC_USE_SCRIPT', True)
     if SCons.Util.is_String(use_script):
         debug('vc.py:msvc_setup_env() use_script 1 %s\n' % repr(use_script))
         d = script_env(use_script)
-    elif use_script:      
+    elif use_script:
         d = msvc_find_valid_batch_script(env,version)
         debug('vc.py:msvc_setup_env() use_script 2 %s\n' % d)
         if not d:
@@ -524,4 +523,3 @@ def msvc_exists(version=None):
     if version is None:
         return len(vcs) > 0
     return version in vcs
-    
diff --git a/src/engine/SCons/Tool/MSCommon/vs.py b/src/engine/SCons/Tool/MSCommon/vs.py
index 0bdbf0c..31197ef 100644
--- a/src/engine/SCons/Tool/MSCommon/vs.py
+++ b/src/engine/SCons/Tool/MSCommon/vs.py
@@ -31,7 +31,7 @@ import os
 import SCons.Errors
 import SCons.Util
 
-from common import debug, \
+from .common import debug, \
                    get_output, \
                    is_win64, \
                    normalize_env, \
@@ -83,10 +83,10 @@ class VisualStudio(object):
             key = root + key
             try:
                 comps = read_reg(key)
-            except SCons.Util.WinError, e:
-                debug('find_vs_dir_by_reg(): no VS registry key %s' % repr(key))
+            except SCons.Util.WinError as e:
+                debug('find_vs_dir_by_reg(): no VS registry key {}'.format(repr(key)))
             else:
-                debug('find_vs_dir_by_reg(): found VS in registry: %s' % comps)
+                debug('find_vs_dir_by_reg(): found VS in registry: {}'.format(comps))
                 return comps
         return None
 
@@ -105,12 +105,12 @@ class VisualStudio(object):
     def find_executable(self):
         vs_dir = self.get_vs_dir()
         if not vs_dir:
-            debug('find_executable():  no vs_dir (%s)'%vs_dir)
+            debug('find_executable():  no vs_dir ({})'.format(vs_dir))
             return None
         executable = os.path.join(vs_dir, self.executable_path)
         executable = os.path.normpath(executable)
         if not os.path.isfile(executable):
-            debug('find_executable():  %s not on file system' % executable)
+            debug('find_executable():  {} not on file system'.format(executable))
             return None
         return executable
 
@@ -209,7 +209,7 @@ SupportedVSList = [
                  batch_file_path=r'Common7\Tools\vsvars32.bat',
                  supported_arch=['x86', 'amd64', "arm"],
     ),
- 
+
     # Visual C++ 2015 Express Edition (for Desktop)
     VisualStudio('14.0Exp',
                  vc_version='14.0',
diff --git a/src/engine/SCons/Tool/__init__.py b/src/engine/SCons/Tool/__init__.py
index f16e9e2..45d0aa1 100644
--- a/src/engine/SCons/Tool/__init__.py
+++ b/src/engine/SCons/Tool/__init__.py
@@ -38,11 +38,13 @@ tool definition.
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import imp
+import importlib
 import sys
 import re
 import os
 import shutil
 
+
 import SCons.Builder
 import SCons.Errors
 import SCons.Node.FS
@@ -52,6 +54,7 @@ import SCons.Scanner.D
 import SCons.Scanner.LaTeX
 import SCons.Scanner.Prog
 import SCons.Scanner.SWIG
+import collections
 
 DefaultToolpath=[]
 
@@ -112,30 +115,62 @@ class Tool(object):
         oldpythonpath = sys.path
         sys.path = self.toolpath + sys.path
 
-        try:
+
+        if sys.version_info[0] < 3:
+            # Py 2 code
             try:
-                file, path, desc = imp.find_module(self.name, self.toolpath)
                 try:
-                    return imp.load_module(self.name, file, path, desc)
-                finally:
-                    if file:
-                        file.close()
-            except ImportError, e:
-                if str(e)!="No module named %s"%self.name:
-                    raise SCons.Errors.EnvironmentError(e)
+                    file, path, desc = imp.find_module(self.name, self.toolpath)
+                    try:
+                        return imp.load_module(self.name, file, path, desc)
+
+                    finally:
+                        if file:
+                            file.close()
+                except ImportError as e:
+                    if str(e)!="No module named %s"%self.name:
+                        raise SCons.Errors.EnvironmentError(e)
+                    try:
+                        import zipimport
+                    except ImportError:
+                        pass
+                    else:
+                        for aPath in self.toolpath:
+                            try:
+                                importer = zipimport.zipimporter(aPath)
+                                return importer.load_module(self.name)
+                            except ImportError as e:
+                                pass
+            finally:
+                sys.path = oldpythonpath
+        else:
+            # Py 3 code
+            try:
+                # Try site_tools first
+                return importlib.import_module(self.name)
+            except ImportError as e:
+                # Then try modules in main distribution
                 try:
-                    import zipimport
-                except ImportError:
-                    pass
-                else:
-                    for aPath in self.toolpath:
-                        try:
-                            importer = zipimport.zipimporter(aPath)
-                            return importer.load_module(self.name)
-                        except ImportError, e:
-                            pass
-        finally:
-            sys.path = oldpythonpath
+                    return importlib.import_module('SCons.Tool.'+self.name)
+                except ImportError as e:
+                    if str(e) != "No module named %s" % self.name:
+                        raise SCons.Errors.EnvironmentError(e)
+                    try:
+                        import zipimport
+                    except ImportError:
+                        pass
+                    else:
+                        for aPath in self.toolpath:
+                            try:
+                                importer = zipimport.zipimporter(aPath)
+                                return importer.load_module(self.name)
+                            except ImportError as e:
+                                pass
+
+            finally:
+                sys.path = oldpythonpath
+
+
 
         full_name = 'SCons.Tool.' + self.name
         try:
@@ -150,7 +185,7 @@ class Tool(object):
                     if file:
                         file.close()
                     return module
-                except ImportError, e:
+                except ImportError as e:
                     if str(e)!="No module named %s"%self.name:
                         raise SCons.Errors.EnvironmentError(e)
                     try:
@@ -159,10 +194,10 @@ class Tool(object):
                         module = importer.load_module(full_name)
                         setattr(SCons.Tool, self.name, module)
                         return module
-                    except ImportError, e:
+                    except ImportError as e:
                         m = "No tool named '%s': %s" % (self.name, e)
                         raise SCons.Errors.EnvironmentError(m)
-            except ImportError, e:
+            except ImportError as e:
                 m = "No tool named '%s': %s" % (self.name, e)
                 raise SCons.Errors.EnvironmentError(m)
 
@@ -254,22 +289,22 @@ def _call_linker_cb(env, callback, args, result = None):
     Verbose = False
 
     if Verbose:
-        print '_call_linker_cb: args=%r' % args
-        print '_call_linker_cb: callback=%r' % callback
+        print('_call_linker_cb: args=%r' % args)
+        print('_call_linker_cb: callback=%r' % callback)
     
     try:
         cbfun = env['LINKCALLBACKS'][callback]
     except (KeyError, TypeError):
         if Verbose:
-            print '_call_linker_cb: env["LINKCALLBACKS"][%r] not found or can not be used' % callback
+            print('_call_linker_cb: env["LINKCALLBACKS"][%r] not found or can not be used' % callback)
         pass
     else:
         if Verbose:
-            print '_call_linker_cb: env["LINKCALLBACKS"][%r] found' % callback
-            print '_call_linker_cb: env["LINKCALLBACKS"][%r]=%r' % (callback, cbfun)
-        if(callable(cbfun)):
+            print('_call_linker_cb: env["LINKCALLBACKS"][%r] found' % callback)
+            print('_call_linker_cb: env["LINKCALLBACKS"][%r]=%r' % (callback, cbfun))
+        if(isinstance(cbfun, collections.Callable)):
             if Verbose:
-                print '_call_linker_cb: env["LINKCALLBACKS"][%r] is callable' % callback
+                print('_call_linker_cb: env["LINKCALLBACKS"][%r] is callable' % callback)
             result = cbfun(env, *args)
     return result
 
@@ -407,17 +442,17 @@ class _LibPrefixGenerator(_LibInfoGeneratorBase):
 
         prefix = self.get_lib_prefix(env,**kw2)
         if Verbose:
-            print "_LibPrefixGenerator: input prefix=%r" % prefix
+            print("_LibPrefixGenerator: input prefix=%r" % prefix)
 
         version = self.get_lib_version(env, **kw2)
         if Verbose:
-            print "_LibPrefixGenerator: version=%r" % version
+            print("_LibPrefixGenerator: version=%r" % version)
 
         if version:
             prefix = self.generate_versioned_lib_info(env, [prefix, version], prefix, **kw2)
 
         if Verbose:
-            print "_LibPrefixGenerator: return prefix=%r" % prefix
+            print("_LibPrefixGenerator: return prefix=%r" % prefix)
         return prefix
 
 ShLibPrefixGenerator  = _LibPrefixGenerator('ShLib')
@@ -441,17 +476,17 @@ class _LibSuffixGenerator(_LibInfoGeneratorBase):
 
         suffix = self.get_lib_suffix(env, **kw2)
         if Verbose:
-            print "_LibSuffixGenerator: input suffix=%r" % suffix
+            print("_LibSuffixGenerator: input suffix=%r" % suffix)
 
         version = self.get_lib_version(env, **kw2)
         if Verbose:
-            print "_LibSuffixGenerator: version=%r" % version
+            print("_LibSuffixGenerator: version=%r" % version)
 
         if version:
             suffix = self.generate_versioned_lib_info(env, [suffix, version], suffix, **kw2)
 
         if Verbose:
-            print "_LibSuffixGenerator: return suffix=%r" % suffix
+            print("_LibSuffixGenerator: return suffix=%r" % suffix)
         return suffix
 
 ShLibSuffixGenerator  = _LibSuffixGenerator('ShLib')
@@ -474,15 +509,15 @@ class _LibSymlinkGenerator(_LibInfoGeneratorBase):
             kw2 = kw
 
         if Verbose:
-            print "_LibSymLinkGenerator: libnode=%r" % libnode.get_path()
+            print("_LibSymLinkGenerator: libnode=%r" % libnode.get_path())
 
         symlinks = None
 
         version = self.get_lib_version(env, **kw2)
         disable = self.get_lib_noversionsymlinks(env, **kw2)
         if Verbose:
-            print '_LibSymlinkGenerator: version=%r' % version
-            print '_LibSymlinkGenerator: disable=%r' % disable
+            print('_LibSymlinkGenerator: version=%r' % version)
+            print('_LibSymlinkGenerator: disable=%r' % disable)
 
         if version and not disable:
             prefix = self.get_lib_prefix(env,**kw2)
@@ -490,7 +525,7 @@ class _LibSymlinkGenerator(_LibInfoGeneratorBase):
             symlinks = self.generate_versioned_lib_info(env, [libnode, version, prefix, suffix], **kw2)
 
         if Verbose:
-            print '_LibSymlinkGenerator: return symlinks=%r' % StringizeLibSymlinks(symlinks)
+            print('_LibSymlinkGenerator: return symlinks=%r' % StringizeLibSymlinks(symlinks))
         return symlinks
 
 ShLibSymlinkGenerator =  _LibSymlinkGenerator('ShLib')
@@ -525,11 +560,11 @@ class _LibNameGenerator(_LibInfoGeneratorBase):
             kw2 = kw
 
         if Verbose:
-            print "_LibNameGenerator: libnode=%r" % libnode.get_path()
+            print("_LibNameGenerator: libnode=%r" % libnode.get_path())
 
         version = self.get_lib_version(env, **kw2)
         if Verbose:
-            print '_LibNameGenerator: version=%r' % version
+            print('_LibNameGenerator: version=%r' % version)
 
         name = None
         if version:
@@ -541,7 +576,7 @@ class _LibNameGenerator(_LibInfoGeneratorBase):
             name = os.path.basename(libnode.get_path())
 
         if Verbose:
-            print '_LibNameGenerator: return name=%r' % name
+            print('_LibNameGenerator: return name=%r' % name)
 
         return name
 
@@ -566,13 +601,13 @@ class _LibSonameGenerator(_LibInfoGeneratorBase):
             kw2 = kw
 
         if Verbose:
-            print "_LibSonameGenerator: libnode=%r" % libnode.get_path()
+            print("_LibSonameGenerator: libnode=%r" % libnode.get_path())
 
         soname = _call_env_subst(env, '$SONAME', **kw2)
         if not soname:
             version = self.get_lib_version(env,**kw2)
             if Verbose:
-                print "_LibSonameGenerator: version=%r" % version
+                print("_LibSonameGenerator: version=%r" % version)
             if version:
                 prefix = self.get_lib_prefix(env,**kw2)
                 suffix = self.get_lib_suffix(env,**kw2)
@@ -582,10 +617,10 @@ class _LibSonameGenerator(_LibInfoGeneratorBase):
             # fallback to library name (as returned by appropriate _LibNameGenerator)
             soname = _LibNameGenerator(self.get_libtype())(env, libnode)
             if Verbose:
-                print "_LibSonameGenerator: FALLBACK: soname=%r" % soname
+                print("_LibSonameGenerator: FALLBACK: soname=%r" % soname)
 
         if Verbose:
-            print "_LibSonameGenerator: return soname=%r" % soname
+            print("_LibSonameGenerator: return soname=%r" % soname)
 
         return soname
 
@@ -617,11 +652,11 @@ def EmitLibSymlinks(env, symlinks, libnode, **kw):
     for link, linktgt in symlinks:
         env.SideEffect(link, linktgt)
         if(Verbose):
-            print "EmitLibSymlinks: SideEffect(%r,%r)" % (link.get_path(), linktgt.get_path())
-        clean_list = filter(lambda x : x != linktgt, nodes)
+            print("EmitLibSymlinks: SideEffect(%r,%r)" % (link.get_path(), linktgt.get_path()))
+        clean_list = [x for x in nodes if x != linktgt]
         env.Clean(list(set([linktgt] + clean_targets)), clean_list)
         if(Verbose):
-            print "EmitLibSymlinks: Clean(%r,%r)" % (linktgt.get_path(), map(lambda x : x.get_path(), clean_list))
+            print("EmitLibSymlinks: Clean(%r,%r)" % (linktgt.get_path(), [x.get_path() for x in clean_list]))
 
 def CreateLibSymlinks(env, symlinks):
     """Physically creates symlinks. The symlinks argument must be a list in
@@ -634,18 +669,18 @@ def CreateLibSymlinks(env, symlinks):
         linktgt = link.get_dir().rel_path(linktgt)
         link = link.get_path()
         if(Verbose):
-            print "CreateLibSymlinks: preparing to add symlink %r -> %r" % (link, linktgt)
+            print("CreateLibSymlinks: preparing to add symlink %r -> %r" % (link, linktgt))
         # Delete the (previously created) symlink if exists. Let only symlinks
         # to be deleted to prevent accidental deletion of source files...
         if env.fs.islink(link):
             env.fs.unlink(link)
             if(Verbose):
-                print "CreateLibSymlinks: removed old symlink %r" % link
+                print("CreateLibSymlinks: removed old symlink %r" % link)
         # If a file or directory exists with the same name as link, an OSError
         # will be thrown, which should be enough, I think.
         env.fs.symlink(linktgt, link)
         if(Verbose):
-            print "CreateLibSymlinks: add symlink %r -> %r" % (link, linktgt)
+            print("CreateLibSymlinks: add symlink %r -> %r" % (link, linktgt))
     return 0
 
 def LibSymlinksActionFunction(target, source, env):
@@ -949,7 +984,7 @@ class ToolInitializer(object):
         so we no longer copy and re-bind them when the construction
         environment gets cloned.
         """
-        for method in self.methods.values():
+        for method in list(self.methods.values()):
             env.RemoveMethod(method)
 
     def apply_tools(self, env):
diff --git a/src/engine/SCons/Tool/aixcc.py b/src/engine/SCons/Tool/aixcc.py
index a89a97e..09365b1 100644
--- a/src/engine/SCons/Tool/aixcc.py
+++ b/src/engine/SCons/Tool/aixcc.py
@@ -36,7 +36,7 @@ import os.path
 
 import SCons.Platform.aix
 
-import cc
+from . import cc
 
 packages = ['vac.C', 'ibmcxx.cmp']
 
diff --git a/src/engine/SCons/Tool/aixf77.py b/src/engine/SCons/Tool/aixf77.py
index cf07a0b..3e30cd0 100644
--- a/src/engine/SCons/Tool/aixf77.py
+++ b/src/engine/SCons/Tool/aixf77.py
@@ -36,7 +36,7 @@ import os.path
 
 #import SCons.Platform.aix
 
-import f77
+from . import f77
 
 # It would be good to look for the AIX F77 package the same way we're now
 # looking for the C and C++ packages.  This should be as easy as supplying
diff --git a/src/engine/SCons/Tool/aixlink.py b/src/engine/SCons/Tool/aixlink.py
index 4e9db21..bfddf0a 100644
--- a/src/engine/SCons/Tool/aixlink.py
+++ b/src/engine/SCons/Tool/aixlink.py
@@ -37,7 +37,8 @@ import os.path
 
 import SCons.Util
 
-import link
+from . import aixcc
+from . import link
 
 cplusplus = __import__('c++', globals(), locals(), [])
 
diff --git a/src/engine/SCons/Tool/applelink.py b/src/engine/SCons/Tool/applelink.py
index 1939098..ba955a4 100644
--- a/src/engine/SCons/Tool/applelink.py
+++ b/src/engine/SCons/Tool/applelink.py
@@ -37,7 +37,7 @@ import SCons.Util
 
 # Even though the Mac is based on the GNU toolchain, it doesn't understand
 # the -rpath option, so we use the "link" tool instead of "gnulink".
-import link
+from . import link
 
 def generate(env):
     """Add Builders and construction variables for applelink to an
diff --git a/src/engine/SCons/Tool/cvf.py b/src/engine/SCons/Tool/cvf.py
index 2a28e6a..da2c910 100644
--- a/src/engine/SCons/Tool/cvf.py
+++ b/src/engine/SCons/Tool/cvf.py
@@ -29,7 +29,7 @@ Tool-specific initialization for the Compaq Visual Fortran compiler.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import fortran
+from . import fortran
 
 compilers = ['f90']
 
diff --git a/src/engine/SCons/Tool/cyglink.py b/src/engine/SCons/Tool/cyglink.py
index 921f0eb..f69b886 100644
--- a/src/engine/SCons/Tool/cyglink.py
+++ b/src/engine/SCons/Tool/cyglink.py
@@ -7,6 +7,9 @@ It will usually be imported through the generic SCons.Tool.Tool()
 selection method.
 
 """
+
+from __future__ import absolute_import, print_function
+
 import re
 import os
 
@@ -14,12 +17,13 @@ import SCons.Action
 import SCons.Util
 import SCons.Tool
 
-import gnulink
-import link
+#MAYBE:  from . import gnulink
+from . import gnulink
+from . import link
 
 def _lib_generator(target, source, env, for_signature, **kw):
     try: cmd = kw['cmd']
-    except KeyError: cmd = SCons.Util.CLVar(['$SHLINK']) 
+    except KeyError: cmd = SCons.Util.CLVar(['$SHLINK'])
 
     try: vp = kw['varprefix']
     except KeyError: vp = 'SHLIB'
@@ -40,7 +44,7 @@ def _lib_generator(target, source, env, for_signature, **kw):
             ])
     else:
         cmd.extend(['$SOURCES', '$_LIBDIRFLAGS', '$_LIBFLAGS'])
-    
+
     return [cmd]
 
 
@@ -58,37 +62,37 @@ def _lib_emitter(target, source, env, **kw):
     Verbose = False
 
     if Verbose:
-        print "_lib_emitter: target[0]=%r" % target[0].get_path()
+        print("_lib_emitter: target[0]=%r" % target[0].get_path())
 
     try: vp = kw['varprefix']
     except KeyError: vp = 'SHLIB'
 
     try: libtype = kw['libtype']
     except KeyError: libtype = 'ShLib'
-        
+
     dll = env.FindIxes(target, '%sPREFIX' % vp, '%sSUFFIX' % vp)
     no_import_lib = env.get('no_import_lib', 0)
 
     if Verbose:
-        print "_lib_emitter: dll=%r" % dll.get_path()
+        print("_lib_emitter: dll=%r" % dll.get_path())
 
     if not dll or len(target) > 1:
         raise SCons.Errors.UserError("A shared library should have exactly one target with the suffix: %s" % env.subst("$%sSUFFIX" % vp))
-    
+
     # Remove any "lib" after the prefix
     pre = env.subst('$%sPREFIX' % vp)
     if dll.name[len(pre):len(pre)+3] == 'lib':
         dll.name = pre + dll.name[len(pre)+3:]
 
     if Verbose:
-        print "_lib_emitter: dll.name=%r" % dll.name
+        print("_lib_emitter: dll.name=%r" % dll.name)
 
     orig_target = target
     target = [env.fs.File(dll)]
     target[0].attributes.shared = 1
 
     if Verbose:
-        print "_lib_emitter: after target=[env.fs.File(dll)]: target[0]=%r" % target[0].get_path()
+        print("_lib_emitter: after target=[env.fs.File(dll)]: target[0]=%r" % target[0].get_path())
 
     # Append an import lib target
     if not no_import_lib:
@@ -97,11 +101,11 @@ def _lib_emitter(target, source, env, **kw):
                                          '%sPREFIX' % vp, '%sSUFFIX' % vp,
                                          'IMPLIBPREFIX', 'IMPLIBSUFFIX')
         if Verbose:
-            print "_lib_emitter: target_strings=%r" % target_strings
-        
+            print("_lib_emitter: target_strings=%r" % target_strings)
+
         implib_target = env.fs.File(target_strings)
         if Verbose:
-            print "_lib_emitter: implib_target=%r" % implib_target.get_path()
+            print("_lib_emitter: implib_target=%r" % implib_target.get_path())
         implib_target.attributes.shared = 1
         target.append(implib_target)
 
@@ -109,7 +113,7 @@ def _lib_emitter(target, source, env, **kw):
                                                  implib_libtype=libtype,
                                                  generator_libtype=libtype+'ImpLib')
     if Verbose:
-        print "_lib_emitter: implib symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks)
+        print("_lib_emitter: implib symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks))
     if symlinks:
         SCons.Tool.EmitLibSymlinks(env, symlinks, implib_target, clean_targets = target[0])
         implib_target.attributes.shliblinks = symlinks
@@ -121,19 +125,19 @@ def shlib_emitter(target, source, env):
 
 def ldmod_emitter(target, source, env):
     return _lib_emitter(target, source, env, varprefix='LDMODULE', libtype='LdMod')
-                         
+
 def _versioned_lib_suffix(env, suffix, version):
     """Generate versioned shared library suffix from a unversioned one.
        If suffix='.dll', and version='0.1.2', then it returns '-0-1-2.dll'"""
     Verbose = False
     if Verbose:
-        print "_versioned_lib_suffix: suffix= ", suffix
-        print "_versioned_lib_suffix: version= ", version
+        print("_versioned_lib_suffix: suffix= ", suffix)
+        print("_versioned_lib_suffix: version= ", version)
     cygversion = re.sub('\.', '-', version)
     if not suffix.startswith('-' + cygversion):
         suffix = '-' + cygversion + suffix
     if Verbose:
-        print "_versioned_lib_suffix: return suffix= ", suffix
+        print("_versioned_lib_suffix: return suffix= ", suffix)
     return suffix
 
 def _versioned_implib_name(env, libnode, version, prefix, suffix, **kw):
@@ -149,8 +153,8 @@ def _versioned_implib_symlinks(env, libnode, version, prefix, suffix, **kw):
     Verbose = False
 
     if Verbose:
-        print "_versioned_implib_symlinks: libnode=%r" % libnode.get_path()
-        print "_versioned_implib_symlinks: version=%r" % version
+        print("_versioned_implib_symlinks: libnode=%r" % libnode.get_path())
+        print("_versioned_implib_symlinks: version=%r" % version)
 
     try: libtype = kw['libtype']
     except KeyError: libtype = 'ShLib'
@@ -158,13 +162,13 @@ def _versioned_implib_symlinks(env, libnode, version, prefix, suffix, **kw):
 
     linkdir = os.path.dirname(libnode.get_path())
     if Verbose:
-        print "_versioned_implib_symlinks: linkdir=%r" % linkdir
+        print("_versioned_implib_symlinks: linkdir=%r" % linkdir)
 
     name = SCons.Tool.ImpLibNameGenerator(env, libnode,
                                           implib_libtype=libtype,
                                           generator_libtype=libtype+'ImpLib')
     if Verbose:
-        print "_versioned_implib_symlinks: name=%r" % name
+        print("_versioned_implib_symlinks: name=%r" % name)
 
     major = version.split('.')[0]
 
@@ -172,7 +176,7 @@ def _versioned_implib_symlinks(env, libnode, version, prefix, suffix, **kw):
     symlinks = [(link0, libnode)]
 
     if Verbose:
-        print "_versioned_implib_symlinks: return symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks)
+        print("_versioned_implib_symlinks: return symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks))
 
     return symlinks
 
diff --git a/src/engine/SCons/Tool/docbook/__init__.py b/src/engine/SCons/Tool/docbook/__init__.py
index 71e93a7..2b22e17 100644
--- a/src/engine/SCons/Tool/docbook/__init__.py
+++ b/src/engine/SCons/Tool/docbook/__init__.py
@@ -335,7 +335,7 @@ def __build_lxml(target, source, env):
         result = transform(doc)
         
     try:
-        of = open(str(target[0]), "w")
+        of = open(str(target[0]), "wb")
         of.write(of.write(etree.tostring(result, pretty_print=True)))
         of.close()
     except:
diff --git a/src/engine/SCons/Tool/docbook/docbook-xsl-1.76.1/extensions/docbook.py b/src/engine/SCons/Tool/docbook/docbook-xsl-1.76.1/extensions/docbook.py
index c070602..e7b8cfa 100644
--- a/src/engine/SCons/Tool/docbook/docbook-xsl-1.76.1/extensions/docbook.py
+++ b/src/engine/SCons/Tool/docbook/docbook-xsl-1.76.1/extensions/docbook.py
@@ -1,5 +1,6 @@
 # docbook.py: extension module
 # $Id: docbook.py 8353 2009-03-17 16:57:50Z mzjn $
+from __future__ import print_function
 
 import sys
 import string
@@ -82,7 +83,7 @@ def adjustColumnWidths(ctx, nodeset):
         relParts.append(relPart)
         absParts.append(pixels)
 
-        col = col.next
+        col = col.__next__
 
     # Ok, now we have the relative widths and absolute widths in
     # two parallel arrays.
@@ -116,7 +117,7 @@ def adjustColumnWidths(ctx, nodeset):
             pixelWidth = convertLength(tableWidth)
 
         if pixelWidth <= absTotal:
-            print "Table is wider than table width"
+            print("Table is wider than table width")
         else:
             pixelWidth = pixelWidth - absTotal
 
@@ -151,7 +152,7 @@ def adjustColumnWidths(ctx, nodeset):
             col.setProp("width", widths[count])
 
         count = count+1
-        col = col.next
+        col = col.__next__
 
     return nodeset
 
@@ -163,10 +164,10 @@ def convertLength(length):
     m = re.search('([+-]?[\d\.]+)(\S+)', length)
     if m != None and m.lastindex > 1:
         unit = pixelsPerInch
-        if unitHash.has_key(m.group(2)):
+        if m.group(2) in unitHash:
             unit = unitHash[m.group(2)]
         else:
-            print "Unrecognized length: " + m.group(2)
+            print("Unrecognized length: " + m.group(2))
 
         pixels = unit * float(m.group(1))
     else:
diff --git a/src/engine/SCons/Tool/docbook/docbook-xsl-1.76.1/extensions/xslt.py b/src/engine/SCons/Tool/docbook/docbook-xsl-1.76.1/extensions/xslt.py
index c712f65..77ca0de 100644
--- a/src/engine/SCons/Tool/docbook/docbook-xsl-1.76.1/extensions/xslt.py
+++ b/src/engine/SCons/Tool/docbook/docbook-xsl-1.76.1/extensions/xslt.py
@@ -1,5 +1,6 @@
 #!/usr/bin/python -u
 # $Id: xslt.py 8353 2009-03-17 16:57:50Z mzjn $
+from __future__ import print_function
 
 import sys
 import libxml2
@@ -18,7 +19,7 @@ try:
     xmlfile = sys.argv[1]
     xslfile = sys.argv[2]
 except IndexError:
-    print usage
+    print(usage)
     sys.exit(1)
 
 def quote(astring):
@@ -38,12 +39,12 @@ try:
     while (sys.argv[count]):
         try:
             name, value = sys.argv[count].split("=", 2)
-            if params.has_key(name):
-                print "Warning: '%s' re-specified; replacing value" % name
+            if name in params:
+                print("Warning: '%s' re-specified; replacing value" % name)
             params[name] = quote(value)
         except ValueError:
-            print "Invalid parameter specification: '" + sys.argv[count] + "'"
-            print usage
+            print("Invalid parameter specification: '" + sys.argv[count] + "'")
+            print(usage)
             sys.exit(1)
         count = count+1
 except IndexError:
@@ -70,7 +71,7 @@ result = style.applyStylesheet(doc, params)
 if outfile:
     style.saveResultToFilename(outfile, result, 0)
 else:
-    print result
+    print(result)
 
 # Free things up
 style.freeStylesheet()
diff --git a/src/engine/SCons/Tool/dvipdf.py b/src/engine/SCons/Tool/dvipdf.py
index 7c41e9c..374b9c5 100644
--- a/src/engine/SCons/Tool/dvipdf.py
+++ b/src/engine/SCons/Tool/dvipdf.py
@@ -100,7 +100,7 @@ def generate(env):
     if DVIPDFAction is None:
         DVIPDFAction = SCons.Action.Action(DviPdfFunction, strfunction = DviPdfStrFunction)
 
-    import pdf
+    from . import pdf
     pdf.generate(env)
 
     bld = env['BUILDERS']['PDF']
diff --git a/src/engine/SCons/Tool/f03.py b/src/engine/SCons/Tool/f03.py
index 3aab1c0..6c30971 100644
--- a/src/engine/SCons/Tool/f03.py
+++ b/src/engine/SCons/Tool/f03.py
@@ -36,7 +36,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 import SCons.Defaults
 import SCons.Tool
 import SCons.Util
-import fortran
+from . import fortran
 from SCons.Tool.FortranCommon import add_all_to_env, add_f03_to_env
 
 compilers = ['f03']
diff --git a/src/engine/SCons/Tool/f08.py b/src/engine/SCons/Tool/f08.py
index a45a61d..7fa5872 100644
--- a/src/engine/SCons/Tool/f08.py
+++ b/src/engine/SCons/Tool/f08.py
@@ -8,6 +8,8 @@ selection method.
 
 """
 
+from __future__ import absolute_import
+
 #
 # __COPYRIGHT__
 #
@@ -36,7 +38,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 import SCons.Defaults
 import SCons.Tool
 import SCons.Util
-import fortran
+from . import fortran
 from SCons.Tool.FortranCommon import add_all_to_env, add_f08_to_env
 
 compilers = ['f08']
diff --git a/src/engine/SCons/Tool/f95.py b/src/engine/SCons/Tool/f95.py
index 5ce5e57..5baa31e 100644
--- a/src/engine/SCons/Tool/f95.py
+++ b/src/engine/SCons/Tool/f95.py
@@ -36,7 +36,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 import SCons.Defaults
 import SCons.Tool
 import SCons.Util
-import fortran
+from . import fortran
 from SCons.Tool.FortranCommon import add_all_to_env, add_f95_to_env
 
 compilers = ['f95']
diff --git a/src/engine/SCons/Tool/filesystem.py b/src/engine/SCons/Tool/filesystem.py
index 31c8abc..3b8ee4c 100644
--- a/src/engine/SCons/Tool/filesystem.py
+++ b/src/engine/SCons/Tool/filesystem.py
@@ -66,7 +66,7 @@ def generate(env):
     try:
         env['BUILDERS']['CopyTo']
         env['BUILDERS']['CopyAs']
-    except KeyError, e:
+    except KeyError as e:
         global copyToBuilder
         if copyToBuilder is None:
             copyToBuilder = SCons.Builder.Builder(
diff --git a/src/engine/SCons/Tool/g++.py b/src/engine/SCons/Tool/g++.py
index 5cf3827..c5eb579 100644
--- a/src/engine/SCons/Tool/g++.py
+++ b/src/engine/SCons/Tool/g++.py
@@ -40,9 +40,8 @@ import subprocess
 import SCons.Tool
 import SCons.Util
 
-import gcc
-
-cplusplus = __import__('c++', globals(), locals(), [])
+from . import gcc
+cplusplus = __import__(__package__+'.c++', globals(), locals(), ['*'])
 
 compilers = ['g++']
 
diff --git a/src/engine/SCons/Tool/gas.py b/src/engine/SCons/Tool/gas.py
index 28f84db..d01bd60 100644
--- a/src/engine/SCons/Tool/gas.py
+++ b/src/engine/SCons/Tool/gas.py
@@ -33,7 +33,10 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-as_module = __import__('as', globals(), locals(), [])
+try:
+    as_module = __import__('as', globals(), locals(), [])
+except:
+    as_module = __import__(__package__+'.as', globals(), locals(), ['*'])
 
 assemblers = ['as', 'gas']
 
diff --git a/src/engine/SCons/Tool/gcc.py b/src/engine/SCons/Tool/gcc.py
index df65647..998e35b 100644
--- a/src/engine/SCons/Tool/gcc.py
+++ b/src/engine/SCons/Tool/gcc.py
@@ -33,7 +33,7 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import cc
+from . import cc
 import os
 import re
 import subprocess
@@ -80,13 +80,13 @@ def detect_version(env, cc):
     #line = pipe.stdout.read().strip()
     #if line:
     #    version = line
-    line = pipe.stdout.readline()
+    line = SCons.Util.to_str(pipe.stdout.readline())
     match = re.search(r'[0-9]+(\.[0-9]+)+', line)
     if match:
         version = match.group(0)
     # Non-GNU compiler's output (like AIX xlc's) may exceed the stdout buffer:
     # So continue with reading to let the child process actually terminate.
-    while pipe.stdout.readline():
+    while SCons.Util.to_str(pipe.stdout.readline()):
         pass
     ret = pipe.wait()
     if ret != 0:
diff --git a/src/engine/SCons/Tool/gfortran.py b/src/engine/SCons/Tool/gfortran.py
index 392a92e..d33bf52 100644
--- a/src/engine/SCons/Tool/gfortran.py
+++ b/src/engine/SCons/Tool/gfortran.py
@@ -36,7 +36,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
-import fortran
+from . import fortran
 
 def generate(env):
     """Add Builders and construction variables for gfortran to an
diff --git a/src/engine/SCons/Tool/gnulink.py b/src/engine/SCons/Tool/gnulink.py
index 2f1aa03..b1d5088 100644
--- a/src/engine/SCons/Tool/gnulink.py
+++ b/src/engine/SCons/Tool/gnulink.py
@@ -39,7 +39,7 @@ import os
 import sys
 import re
 
-import link
+from . import link
 
 
 def generate(env):
diff --git a/src/engine/SCons/Tool/gs.py b/src/engine/SCons/Tool/gs.py
index 6e31ee2..25359a8 100644
--- a/src/engine/SCons/Tool/gs.py
+++ b/src/engine/SCons/Tool/gs.py
@@ -62,12 +62,12 @@ def generate(env):
         if GhostscriptAction is None:
             GhostscriptAction = SCons.Action.Action('$GSCOM', '$GSCOMSTR')
     
-        import pdf
+        from SCons.Tool import pdf
         pdf.generate(env)
     
         bld = env['BUILDERS']['PDF']
         bld.add_action('.ps', GhostscriptAction)
-    except ImportError, e:
+    except ImportError as e:
         pass
 
     gsbuilder = SCons.Builder.Builder(action = SCons.Action.Action('$GSCOM', '$GSCOMSTR'))
diff --git a/src/engine/SCons/Tool/hpcc.py b/src/engine/SCons/Tool/hpcc.py
index 30f4964..51d2e38 100644
--- a/src/engine/SCons/Tool/hpcc.py
+++ b/src/engine/SCons/Tool/hpcc.py
@@ -34,7 +34,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
-import cc
+from . import cc
 
 def generate(env):
     """Add Builders and construction variables for aCC & cc to an Environment."""
diff --git a/src/engine/SCons/Tool/hplink.py b/src/engine/SCons/Tool/hplink.py
index 17dbe05..10ef30b 100644
--- a/src/engine/SCons/Tool/hplink.py
+++ b/src/engine/SCons/Tool/hplink.py
@@ -37,7 +37,7 @@ import os.path
 
 import SCons.Util
 
-import link
+from . import link
 
 ccLinker = None
 
diff --git a/src/engine/SCons/Tool/icc.py b/src/engine/SCons/Tool/icc.py
index db15642..11ea075 100644
--- a/src/engine/SCons/Tool/icc.py
+++ b/src/engine/SCons/Tool/icc.py
@@ -33,7 +33,7 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import cc
+from . import cc
 
 def generate(env):
     """Add Builders and construction variables for the OS/2 to an Environment."""
diff --git a/src/engine/SCons/Tool/ifl.py b/src/engine/SCons/Tool/ifl.py
index 30b3672..865d2ba 100644
--- a/src/engine/SCons/Tool/ifl.py
+++ b/src/engine/SCons/Tool/ifl.py
@@ -35,7 +35,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Defaults
 from SCons.Scanner.Fortran import FortranScan
-from FortranCommon import add_all_to_env
+from .FortranCommon import add_all_to_env
 
 def generate(env):
     """Add Builders and construction variables for ifl to an Environment."""
diff --git a/src/engine/SCons/Tool/ifort.py b/src/engine/SCons/Tool/ifort.py
index 4b2fd65..638bd12 100644
--- a/src/engine/SCons/Tool/ifort.py
+++ b/src/engine/SCons/Tool/ifort.py
@@ -36,7 +36,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Defaults
 from SCons.Scanner.Fortran import FortranScan
-from FortranCommon import add_all_to_env
+from .FortranCommon import add_all_to_env
 
 def generate(env):
     """Add Builders and construction variables for ifort to an Environment."""
diff --git a/src/engine/SCons/Tool/install.py b/src/engine/SCons/Tool/install.py
index e84ec7a..e16bb5f 100644
--- a/src/engine/SCons/Tool/install.py
+++ b/src/engine/SCons/Tool/install.py
@@ -29,6 +29,7 @@ selection method.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -48,7 +49,7 @@ _UNIQUE_INSTALLED_FILES = None
 
 class CopytreeError(EnvironmentError):
     pass
-                
+
 # This is a patched version of shutil.copytree from python 2.5.  It
 # doesn't fail if the dir exists, which regular copytree does
 # (annoyingly).  Note the XXX comment in the docstring.
@@ -83,21 +84,21 @@ def scons_copytree(src, dst, symlinks=False):
             else:
                 shutil.copy2(srcname, dstname)
             # XXX What about devices, sockets etc.?
-        except (IOError, os.error), why:
+        except (IOError, os.error) as why:
             errors.append((srcname, dstname, str(why)))
         # catch the CopytreeError from the recursive copytree so that we can
         # continue with other files
-        except CopytreeError, err:
+        except CopytreeError as err:
             errors.extend(err.args[0])
     try:
         shutil.copystat(src, dst)
     except SCons.Util.WinError:
         # can't copy file access times on Windows
         pass
-    except OSError, why:
+    except OSError as why:
         errors.extend((src, dst, str(why)))
     if errors:
-        raise CopytreeError, errors
+        raise CopytreeError(errors)
 
 
 #
@@ -165,10 +166,9 @@ def listShlibLinksToInstall(dest, source, env):
 def installShlibLinks(dest, source, env):
     """If we are installing a versioned shared library create the required links."""
     Verbose = False
-
     symlinks = listShlibLinksToInstall(dest, source, env)
     if Verbose:
-        print 'installShlibLinks: symlinks=%r' % SCons.Tool.StringizeLibSymlinks(symlinks)
+        print('installShlibLinks: symlinks={:r}'.format(SCons.Tool.StringizeLibSymlinks(symlinks)))
     if symlinks:
         SCons.Tool.CreateLibSymlinks(env, symlinks)
     return
@@ -244,12 +244,10 @@ def add_versioned_targets_to_INSTALLED_FILES(target, source, env):
     Verbose = False
     _INSTALLED_FILES.extend(target)
     if Verbose:
-        print "add_versioned_targets_to_INSTALLED_FILES: target=%r" % map(str, target)
-
+        print("add_versioned_targets_to_INSTALLED_FILES: target={:r}".format(map(str, target)))
     symlinks = listShlibLinksToInstall(target[0], source, env)
     if symlinks:
         SCons.Tool.EmitLibSymlinks(env, symlinks, target[0])
-        
     _UNIQUE_INSTALLED_FILES = None
     return (target, source)
 
diff --git a/src/engine/SCons/Tool/intelc.py b/src/engine/SCons/Tool/intelc.py
index 20df0f4..b39cae5 100644
--- a/src/engine/SCons/Tool/intelc.py
+++ b/src/engine/SCons/Tool/intelc.py
@@ -30,7 +30,7 @@ selection method.
 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-from __future__ import division
+from __future__ import division, print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -245,17 +245,16 @@ def get_all_compiler_versions():
                         # Registry points to nonexistent dir.  Ignore this
                         # version.
                         value = get_intel_registry_value('ProductDir', subkey, 'IA32')
-                    except MissingRegistryError, e:
+                    except MissingRegistryError as e:
 
                         # Registry key is left dangling (potentially
                         # after uninstalling).
 
-                        print \
-                            "scons: *** Ignoring the registry key for the Intel compiler version %s.\n" \
+                        print("scons: *** Ignoring the registry key for the Intel compiler version %s.\n" \
                             "scons: *** It seems that the compiler was uninstalled and that the registry\n" \
-                            "scons: *** was not cleaned up properly.\n" % subkey
+                            "scons: *** was not cleaned up properly.\n" % subkey)
                     else:
-                        print "scons: *** Ignoring "+str(value)
+                        print("scons: *** Ignoring "+str(value))
 
                 i = i + 1
         except EnvironmentError:
@@ -486,8 +485,8 @@ def generate(env, version=None, abi=None, topdir=None, verbose=0):
             bindir="bin"
             libdir="lib"
         if verbose:
-            print "Intel C compiler: using version %s (%g), abi %s, in '%s/%s'"%\
-                  (repr(version), linux_ver_normalize(version),abi,topdir,bindir)
+            print("Intel C compiler: using version %s (%g), abi %s, in '%s/%s'"%\
+                  (repr(version), linux_ver_normalize(version),abi,topdir,bindir))
             if is_linux:
                 # Show the actual compiler version by running the compiler.
                 os.system('%s/%s/icc --version'%(topdir,bindir))
diff --git a/src/engine/SCons/Tool/latex.py b/src/engine/SCons/Tool/latex.py
index 1c71743..f30356b 100644
--- a/src/engine/SCons/Tool/latex.py
+++ b/src/engine/SCons/Tool/latex.py
@@ -55,10 +55,10 @@ def generate(env):
 
     env.AppendUnique(LATEXSUFFIXES=SCons.Tool.LaTeXSuffixes)
 
-    import dvi
+    from . import dvi
     dvi.generate(env)
 
-    import pdf
+    from . import pdf
     pdf.generate(env)
 
     bld = env['BUILDERS']['DVI']
diff --git a/src/engine/SCons/Tool/link.py b/src/engine/SCons/Tool/link.py
index a4a2a4c..ae2c4b8 100644
--- a/src/engine/SCons/Tool/link.py
+++ b/src/engine/SCons/Tool/link.py
@@ -1,3 +1,4 @@
+
 """SCons.Tool.link
 
 Tool-specific initialization for the generic Posix linker.
@@ -30,6 +31,7 @@ selection method.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -44,8 +46,7 @@ import SCons.Warnings
 from SCons.Tool.FortranCommon import isfortran
 
 from SCons.Tool.DCommon import isD
-
-cplusplus = __import__('c++', globals(), locals(), [])
+cplusplus = __import__(__package__+'.c++', globals(), locals(), ['*'])
 
 issued_mixed_link_warning = False
 
@@ -76,20 +77,20 @@ def smart_link(source, target, env, for_signature):
 def _lib_emitter(target, source, env, **kw):
     Verbose = False
     if Verbose:
-        print "_lib_emitter: target[0]=%r" % target[0].get_path()
+        print("_lib_emitter: target[0]={:r}".format(target[0].get_path()))
     for tgt in target:
         tgt.attributes.shared = 1
-    
+
     try:
         symlink_generator = kw['symlink_generator']
     except KeyError:
         pass
     else:
         if Verbose:
-            print "_lib_emitter: symlink_generator=%r" % symlink_generator
+            print("_lib_emitter: symlink_generator={:r}".format(symlink_generator))
         symlinks = symlink_generator(env, target[0])
         if Verbose:
-            print "_lib_emitter: symlinks=%r" % symlinks 
+            print("_lib_emitter: symlinks={:r}".format(symlinks))
 
         if symlinks:
             SCons.Tool.EmitLibSymlinks(env, symlinks, target[0])
@@ -108,28 +109,28 @@ def _versioned_lib_name(env, libnode, version, prefix, suffix, prefix_generator,
     Verbose = False
 
     if Verbose:
-        print "_versioned_lib_name: libnode=%r" % libnode.get_path()
-        print "_versioned_lib_name: version=%r" % version
-        print "_versioned_lib_name: prefix=%r" % prefix
-        print "_versioned_lib_name: suffix=%r" % suffix
-        print "_versioned_lib_name: suffix_generator=%r" % suffix_generator
+        print("_versioned_lib_name: libnode={:r}".format(libnode.get_path()))
+        print("_versioned_lib_name: version={:r}".format(version))
+        print("_versioned_lib_name: prefix={:r}".format(prefix))
+        print("_versioned_lib_name: suffix={:r}".format(suffix))
+        print("_versioned_lib_name: suffix_generator={:r}".format(suffix_generator))
 
     versioned_name = os.path.basename(libnode.get_path())
     if Verbose:
-        print "_versioned_lib_name: versioned_name=%r" % versioned_name
+        print("_versioned_lib_name: versioned_name={:r}".format(versioned_name))
 
     versioned_prefix = prefix_generator(env, **kw)
     versioned_suffix = suffix_generator(env, **kw)
     if Verbose:
-        print "_versioned_lib_name: versioned_prefix=%r" % versioned_prefix
-        print "_versioned_lib_name: versioned_suffix=%r" % versioned_suffix
+        print("_versioned_lib_name: versioned_prefix={:r}".format(versioned_prefix))
+        print("_versioned_lib_name: versioned_suffix={:r}".format(versioned_suffix))
 
     versioned_prefix_re = '^' + re.escape(versioned_prefix)
     versioned_suffix_re = re.escape(versioned_suffix) + '$'
     name = re.sub(versioned_prefix_re, prefix, versioned_name)
     name = re.sub(versioned_suffix_re, suffix, name)
     if Verbose:
-        print "_versioned_lib_name: name=%r" % name
+        print("_versioned_lib_name: name={:r}".format(name))
     return name
 
 def _versioned_shlib_name(env, libnode, version, prefix, suffix, **kw):
@@ -146,33 +147,33 @@ def _versioned_lib_suffix(env, suffix, version):
     """For suffix='.so' and version='0.1.2' it returns '.so.0.1.2'"""
     Verbose = False
     if Verbose:
-        print "_versioned_lib_suffix: suffix=%r" % suffix
-        print "_versioned_lib_suffix: version=%r" % version
+        print("_versioned_lib_suffix: suffix={:r}".format(suffix))
+        print("_versioned_lib_suffix: version={:r}".format(version))
     if not suffix.endswith(version):
         suffix = suffix + '.' + version
     if Verbose:
-        print "_versioned_lib_suffix: return suffix=%r" % suffix
+        print("_versioned_lib_suffix: return suffix={:r}".format(suffix))
     return suffix
 
 def _versioned_lib_soname(env, libnode, version, prefix, suffix, name_func):
     """For libnode='/optional/dir/libfoo.so.X.Y.Z' it returns 'libfoo.so.X'"""
     Verbose = False
     if Verbose:
-        print "_versioned_lib_soname: version=%r" % version
+        print("_versioned_lib_soname: version={:r}".format(version))
     name = name_func(env, libnode, version, prefix, suffix)
     if Verbose:
-        print "_versioned_lib_soname: name=%r" % name
+        print("_versioned_lib_soname: name={:r}".format(name))
     major = version.split('.')[0]
     soname = name + '.' + major
     if Verbose:
-        print "_versioned_lib_soname: soname=%r" % soname
+        print("_versioned_lib_soname: soname={:r}".format(soname))
     return soname
 
 def _versioned_shlib_soname(env, libnode, version, prefix, suffix):
-    return _versioned_lib_soname(env, libnode, version, prefix, suffix, _versioned_shlib_name) 
+    return _versioned_lib_soname(env, libnode, version, prefix, suffix, _versioned_shlib_name)
 
 def _versioned_ldmod_soname(env, libnode, version, prefix, suffix):
-    return _versioned_lib_soname(env, libnode, version, prefix, suffix, _versioned_ldmod_name) 
+    return _versioned_lib_soname(env, libnode, version, prefix, suffix, _versioned_ldmod_name)
 
 def _versioned_lib_symlinks(env, libnode, version, prefix, suffix, name_func, soname_func):
     """Generate link names that should be created for a versioned shared lirbrary.
@@ -181,23 +182,23 @@ def _versioned_lib_symlinks(env, libnode, version, prefix, suffix, name_func, so
     Verbose = False
 
     if Verbose:
-        print "_versioned_lib_symlinks: libnode=%r" % libnode.get_path()
-        print "_versioned_lib_symlinks: version=%r" % version
+        print("_versioned_lib_symlinks: libnode={:r}".format(libnode.get_path()))
+        print("_versioned_lib_symlinks: version={:r}".format(version))
 
     if sys.platform.startswith('openbsd'):
         # OpenBSD uses x.y shared library versioning numbering convention
         # and doesn't use symlinks to backwards-compatible libraries
         if Verbose:
-            print "_versioned_lib_symlinks: return symlinks=%r" % None
+            print("_versioned_lib_symlinks: return symlinks={:r}".format(None))
         return None
 
     linkdir = libnode.get_dir()
     if Verbose:
-        print "_versioned_lib_symlinks: linkdir=%r" % linkdir.get_path()
+        print("_versioned_lib_symlinks: linkdir={:r}".format(linkdir.get_path()))
 
     name = name_func(env, libnode, version, prefix, suffix)
     if Verbose:
-        print "_versioned_lib_symlinks: name=%r" % name
+        print("_versioned_lib_symlinks: name={:r}".format(name))
 
     soname = soname_func(env, libnode, version, prefix, suffix)
 
@@ -213,7 +214,7 @@ def _versioned_lib_symlinks(env, libnode, version, prefix, suffix, name_func, so
         symlinks = [ (link0, libnode), (link1, libnode) ]
 
     if Verbose:
-        print "_versioned_lib_symlinks: return symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks)
+        print("_versioned_lib_symlinks: return symlinks={:r}".format(SCons.Tool.StringizeLibSymlinks(symlinks)))
 
     return symlinks
 
@@ -247,7 +248,7 @@ def _setup_versioned_lib_variables(env, **kw):
     except KeyError: pass
 
     use_soname = False
-    try: use_soname = kw['use_soname'] 
+    try: use_soname = kw['use_soname']
     except KeyError: pass
 
     # The $_SHLIBVERSIONFLAGS define extra commandline flags used when
diff --git a/src/engine/SCons/Tool/midl.py b/src/engine/SCons/Tool/midl.py
index 64b927a..7a59e33 100644
--- a/src/engine/SCons/Tool/midl.py
+++ b/src/engine/SCons/Tool/midl.py
@@ -39,7 +39,7 @@ import SCons.Defaults
 import SCons.Scanner.IDL
 import SCons.Util
 
-from MSCommon import msvc_exists
+from .MSCommon import msvc_exists
 
 def midl_emitter(target, source, env):
     """Produces a list of outputs from the MIDL compiler"""
diff --git a/src/engine/SCons/Tool/msgfmt.py b/src/engine/SCons/Tool/msgfmt.py
index 352ba77..4fe6afd 100644
--- a/src/engine/SCons/Tool/msgfmt.py
+++ b/src/engine/SCons/Tool/msgfmt.py
@@ -41,7 +41,7 @@ class _MOFileBuilder(BuilderBase):
     import SCons.Util
     from SCons.Tool.GettextCommon import _read_linguas_from_files
     linguas_files = None
-    if env.has_key('LINGUAS_FILE') and env['LINGUAS_FILE'] is not None:
+    if 'LINGUAS_FILE' in env and env['LINGUAS_FILE'] is not None:
       linguas_files = env['LINGUAS_FILE']
       # This should prevent from endless recursion. 
       env['LINGUAS_FILE'] = None
diff --git a/src/engine/SCons/Tool/msginit.py b/src/engine/SCons/Tool/msginit.py
index 5e9c0e4..39f460d 100644
--- a/src/engine/SCons/Tool/msginit.py
+++ b/src/engine/SCons/Tool/msginit.py
@@ -35,7 +35,7 @@ def _optional_no_translator_flag(env):
   """ Return '--no-translator' flag if we run *msginit(1)*  in non-interactive
       mode."""
   import SCons.Util
-  if env.has_key('POAUTOINIT'):
+  if 'POAUTOINIT' in env:
     autoinit = env['POAUTOINIT']
   else:
     autoinit = False
@@ -66,7 +66,7 @@ def _POInitBuilderWrapper(env, target=None, source=_null, **kw):
   if source is _null:
     if 'POTDOMAIN' in kw:
       domain = kw['POTDOMAIN']
-    elif env.has_key('POTDOMAIN'):
+    elif 'POTDOMAIN' in env:
       domain = env['POTDOMAIN']
     else:
       domain = 'messages'
diff --git a/src/engine/SCons/Tool/msgmerge.py b/src/engine/SCons/Tool/msgmerge.py
index f3710ab..11d7b48 100644
--- a/src/engine/SCons/Tool/msgmerge.py
+++ b/src/engine/SCons/Tool/msgmerge.py
@@ -58,7 +58,7 @@ def _POUpdateBuilderWrapper(env, target=None, source=_null, **kw):
   if source is _null:
     if 'POTDOMAIN' in kw:
       domain = kw['POTDOMAIN']
-    elif env.has_key('POTDOMAIN') and env['POTDOMAIN']:
+    elif 'POTDOMAIN' in env and env['POTDOMAIN']:
       domain = env['POTDOMAIN']
     else:
       domain = 'messages'
diff --git a/src/engine/SCons/Tool/mslib.py b/src/engine/SCons/Tool/mslib.py
index 2453979..c5a7a32 100644
--- a/src/engine/SCons/Tool/mslib.py
+++ b/src/engine/SCons/Tool/mslib.py
@@ -39,7 +39,7 @@ import SCons.Tool.msvs
 import SCons.Tool.msvc
 import SCons.Util
 
-from MSCommon import msvc_exists, msvc_setup_env_once
+from .MSCommon import msvc_exists, msvc_setup_env_once
 
 def generate(env):
     """Add Builders and construction variables for lib to an Environment."""
diff --git a/src/engine/SCons/Tool/mslink.py b/src/engine/SCons/Tool/mslink.py
index 74c20d0..55cf33f 100644
--- a/src/engine/SCons/Tool/mslink.py
+++ b/src/engine/SCons/Tool/mslink.py
@@ -30,6 +30,7 @@ selection method.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -44,7 +45,7 @@ import SCons.Tool.msvc
 import SCons.Tool.msvs
 import SCons.Util
 
-from MSCommon import msvc_setup_env_once, msvc_exists
+from .MSCommon import msvc_setup_env_once, msvc_exists
 
 def pdbGenerator(env, target, source, for_signature):
     try:
@@ -191,7 +192,7 @@ def prog_emitter(target, source, env):
         # MSVC 11 and above need the PCH object file to be added to the link line,
         # otherwise you get link error LNK2011.
         pchobj = SCons.Util.splitext(str(env['PCH']))[0] + '.obj'
-        # print "prog_emitter, version %s, appending pchobj %s"%(version_num, pchobj)
+        # print("prog_emitter, version %s, appending pchobj %s"%(version_num, pchobj))
         if pchobj not in extrasources:
             extrasources.append(pchobj)
 
@@ -203,7 +204,7 @@ def RegServerFunc(target, source, env):
         if ret:
             raise SCons.Errors.UserError("Unable to register %s" % target[0])
         else:
-            print "Registered %s sucessfully" % target[0]
+            print("Registered %s sucessfully" % target[0])
         return ret
     return 0
 
@@ -220,10 +221,10 @@ def embedManifestDllCheck(target, source, env):
         if os.path.exists(manifestSrc):
             ret = (embedManifestDllAction) ([target[0]],None,env)        
             if ret:
-                raise SCons.Errors.UserError, "Unable to embed manifest into %s" % (target[0])
+                raise SCons.Errors.UserError("Unable to embed manifest into %s" % (target[0]))
             return ret
         else:
-            print '(embed: no %s.manifest found; not embedding.)'%str(target[0])
+            print('(embed: no %s.manifest found; not embedding.)'%str(target[0]))
     return 0
 
 def embedManifestExeCheck(target, source, env):
@@ -234,10 +235,10 @@ def embedManifestExeCheck(target, source, env):
         if os.path.exists(manifestSrc):
             ret = (embedManifestExeAction) ([target[0]],None,env)
             if ret:
-                raise SCons.Errors.UserError, "Unable to embed manifest into %s" % (target[0])
+                raise SCons.Errors.UserError("Unable to embed manifest into %s" % (target[0]))
             return ret
         else:
-            print '(embed: no %s.manifest found; not embedding.)'%str(target[0])
+            print('(embed: no %s.manifest found; not embedding.)'%str(target[0]))
     return 0
 
 embedManifestDllCheckAction = SCons.Action.Action(embedManifestDllCheck, None)
diff --git a/src/engine/SCons/Tool/mssdk.py b/src/engine/SCons/Tool/mssdk.py
index 6103f30..f373002 100644
--- a/src/engine/SCons/Tool/mssdk.py
+++ b/src/engine/SCons/Tool/mssdk.py
@@ -33,7 +33,7 @@ It will usually be imported through the generic SCons.Tool.Tool()
 selection method.
 """
 
-from MSCommon import mssdk_exists, \
+from .MSCommon import mssdk_exists, \
                      mssdk_setup_env
 
 def generate(env):
diff --git a/src/engine/SCons/Tool/msvc.py b/src/engine/SCons/Tool/msvc.py
index 878ec6e..f894562 100644
--- a/src/engine/SCons/Tool/msvc.py
+++ b/src/engine/SCons/Tool/msvc.py
@@ -47,7 +47,7 @@ import SCons.Util
 import SCons.Warnings
 import SCons.Scanner.RC
 
-from MSCommon import msvc_exists, msvc_setup_env_once
+from .MSCommon import msvc_exists, msvc_setup_env_once
 
 CSuffixes = ['.c', '.C']
 CXXSuffixes = ['.cc', '.cpp', '.cxx', '.c++', '.C++']
diff --git a/src/engine/SCons/Tool/msvs.py b/src/engine/SCons/Tool/msvs.py
index 113f859..6df4928 100644
--- a/src/engine/SCons/Tool/msvs.py
+++ b/src/engine/SCons/Tool/msvs.py
@@ -30,6 +30,8 @@ selection method.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+from __future__ import print_function
+
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.compat
@@ -38,7 +40,6 @@ import base64
 import hashlib
 import ntpath
 import os
-# compat layer imports "cPickle" for us if it's available.
 import pickle
 import re
 import sys
@@ -51,7 +52,7 @@ import SCons.PathList
 import SCons.Util
 import SCons.Warnings
 
-from MSCommon import msvc_exists, msvc_setup_env_once
+from .MSCommon import msvc_exists, msvc_setup_env_once
 from SCons.Defaults import processDefines
 
 ##############################################################################
@@ -70,7 +71,7 @@ def xmlify(s):
 # Returns a tuple of nodes.
 def processIncludes(includes, env, target, source):
     return SCons.PathList.PathList(includes).subst_path(env, target, source)
-    
+
 
 external_makefile_guid = '{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}'
 
@@ -168,15 +169,15 @@ class _UserGenerator(object):
     Base class for .dsp.user file generator
     '''
     # Default instance values.
-    # Ok ... a bit defensive, but it does not seem reasonable to crash the 
+    # Ok ... a bit defensive, but it does not seem reasonable to crash the
     # build for a workspace user file. :-)
     usrhead = None
-    usrdebg = None 
+    usrdebg = None
     usrconf = None
-    createfile = False 
+    createfile = False
     def __init__(self, dspfile, source, env):
         # DebugSettings should be a list of debug dictionary sorted in the same order
-        # as the target list and variants 
+        # as the target list and variants
         if 'variant' not in env:
             raise SCons.Errors.InternalError("You must specify a 'variant' argument (i.e. 'Debug' or " +\
                   "'Release') to create an MSVSProject.")
@@ -184,7 +185,7 @@ class _UserGenerator(object):
             variants = [env['variant']]
         elif SCons.Util.is_List(env['variant']):
             variants = env['variant']
-        
+
         if 'DebugSettings' not in env or env['DebugSettings'] == None:
             dbg_settings = []
         elif SCons.Util.is_Dict(env['DebugSettings']):
@@ -200,12 +201,12 @@ class _UserGenerator(object):
                     dbg_settings.append({})
         else:
             dbg_settings = []
-            
+
         if len(dbg_settings) == 1:
             dbg_settings = dbg_settings * len(variants)
-            
+
         self.createfile = self.usrhead and self.usrdebg and self.usrconf and \
-                            dbg_settings and bool([ds for ds in dbg_settings if ds]) 
+                            dbg_settings and bool([ds for ds in dbg_settings if ds])
 
         if self.createfile:
             dbg_settings = dict(zip(variants, dbg_settings))
@@ -215,22 +216,22 @@ class _UserGenerator(object):
                 for key in [k for k in self.usrdebg.keys() if k in src]:
                     trg[key] = str(src[key])
                 self.configs[var].debug = trg
-    
+
     def UserHeader(self):
         encoding = self.env.subst('$MSVSENCODING')
         versionstr = self.versionstr
         self.usrfile.write(self.usrhead % locals())
-   
+
     def UserProject(self):
         pass
-    
+
     def Build(self):
         if not self.createfile:
             return
         try:
             filename = self.dspabs +'.user'
             self.usrfile = open(filename, 'w')
-        except IOError, detail:
+        except IOError as detail:
             raise SCons.Errors.InternalError('Unable to open "' + filename + '" for writing:' + str(detail))
         else:
             self.UserHeader()
@@ -290,7 +291,7 @@ class _GenerateV7User(_UserGenerator):
             self.usrconf = V9UserConfiguration
             self.usrdebg = V9DebugSettings
         _UserGenerator.__init__(self, dspfile, source, env)
-    
+
     def UserProject(self):
         confkeys = sorted(self.configs.keys())
         for kind in confkeys:
@@ -298,8 +299,8 @@ class _GenerateV7User(_UserGenerator):
             platform = self.configs[kind].platform
             debug = self.configs[kind].debug
             if debug:
-                debug_settings = '\n'.join(['\t\t\t\t%s="%s"' % (key, xmlify(value)) 
-                                            for key, value in debug.items() 
+                debug_settings = '\n'.join(['\t\t\t\t%s="%s"' % (key, xmlify(value))
+                                            for key, value in debug.items()
                                             if value is not None])
                 self.usrfile.write(self.usrconf % locals())
         self.usrfile.write('\t</Configurations>\n</VisualStudioUserFile>')
@@ -345,7 +346,7 @@ V10DebugSettings = {
 
 class _GenerateV10User(_UserGenerator):
     """Generates a Project'user file for MSVS 2010"""
-    
+
     def __init__(self, dspfile, source, env):
         self.versionstr = '4.0'
         self.usrhead = V10UserHeader
@@ -360,8 +361,8 @@ class _GenerateV10User(_UserGenerator):
             platform = self.configs[kind].platform
             debug = self.configs[kind].debug
             if debug:
-                debug_settings = '\n'.join(['\t\t<%s>%s</%s>' % (key, xmlify(value), key) 
-                                            for key, value in debug.items() 
+                debug_settings = '\n'.join(['\t\t<%s>%s</%s>' % (key, xmlify(value), key)
+                                            for key, value in debug.items()
                                             if value is not None])
                 self.usrfile.write(self.usrconf % locals())
         self.usrfile.write('</Project>')
@@ -457,7 +458,7 @@ class _DSPGenerator(object):
                 runfile.append(s)
 
         self.sconscript = env['MSVSSCONSCRIPT']
-        
+
         if 'cmdargs' not in env or env['cmdargs'] == None:
             cmdargs = [''] * len(variants)
         elif SCons.Util.is_String(env['cmdargs']):
@@ -467,7 +468,7 @@ class _DSPGenerator(object):
                 raise SCons.Errors.InternalError("Sizes of 'cmdargs' and 'variant' lists must be the same.")
             else:
                 cmdargs = env['cmdargs']
-                
+
         self.env = env
 
         if 'name' in self.env:
@@ -525,7 +526,7 @@ class _DSPGenerator(object):
                 config.platform = 'Win32'
 
             self.configs[variant] = config
-            print "Adding '" + self.name + ' - ' + config.variant + '|' + config.platform + "' to '" + str(dspfile) + "'"
+            print("Adding '" + self.name + ' - ' + config.variant + '|' + config.platform + "' to '" + str(dspfile) + "'")
 
         for i in range(len(variants)):
             AddConfig(self, variants[i], buildtarget[i], outdir[i], runfile[i], cmdargs[i])
@@ -725,7 +726,7 @@ class _GenerateV6DSP(_DSPGenerator):
     def Build(self):
         try:
             self.file = open(self.dspabs,'w')
-        except IOError, detail:
+        except IOError as detail:
             raise SCons.Errors.InternalError('Unable to open "' + self.dspabs + '" for writing:' + str(detail))
         else:
             self.PrintHeader()
@@ -817,7 +818,7 @@ class _GenerateV7DSP(_DSPGenerator, _GenerateV7User):
             self.dspheader = V7DSPHeader
             self.dspconfiguration = V7DSPConfiguration
         self.file = None
-        
+
         _GenerateV7User.__init__(self, dspfile, source, env)
 
     def PrintHeader(self):
@@ -894,7 +895,7 @@ class _GenerateV7DSP(_DSPGenerator, _GenerateV7User):
             preprocdefs = xmlify(';'.join(processDefines(self.env.get('CPPDEFINES', []))))
             includepath_Dirs = processIncludes(self.env.get('CPPPATH', []), self.env, None, None)
             includepath = xmlify(';'.join([str(x) for x in includepath_Dirs]))
-            
+
             if not env_has_buildtarget:
                 del self.env['MSVSBUILDTARGET']
 
@@ -1037,13 +1038,13 @@ class _GenerateV7DSP(_DSPGenerator, _GenerateV7User):
     def Build(self):
         try:
             self.file = open(self.dspabs,'w')
-        except IOError, detail:
+        except IOError as detail:
             raise SCons.Errors.InternalError('Unable to open "' + self.dspabs + '" for writing:' + str(detail))
         else:
             self.PrintHeader()
             self.PrintProject()
             self.file.close()
-            
+
         _GenerateV7User.Build(self)
 
 V10DSPHeader = """\
@@ -1100,7 +1101,7 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
         self.dspheader = V10DSPHeader
         self.dspconfiguration = V10DSPProjectConfiguration
         self.dspglobals = V10DSPGlobals
-        
+
         _GenerateV10User.__init__(self, dspfile, source, env)
 
     def PrintHeader(self):
@@ -1131,27 +1132,27 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                          '\t\t<SccLocalPath>%s</SccLocalPath>\n' % (scc_project_name, scc_local_path_legacy))
         else:
             self.dspglobals = self.dspglobals.replace('%(scc_attrs)s', '')
-            
+
         self.file.write(self.dspheader % locals())
-        
+
         self.file.write('\t<ItemGroup Label="ProjectConfigurations">\n')
-        
+
         confkeys = sorted(self.configs.keys())
         for kind in confkeys:
             variant = self.configs[kind].variant
             platform = self.configs[kind].platform
             self.file.write(self.dspconfiguration % locals())
-        
+
         self.file.write('\t</ItemGroup>\n')
-        
+
         self.file.write(self.dspglobals % locals())
-    
+
     def PrintProject(self):
         name = self.name
         confkeys = sorted(self.configs.keys())
-             
+
         self.file.write('\t<Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />\n')
-        
+
         toolset = ''
         if 'MSVC_VERSION' in self.env:
             version_num, suite = msvs_parse_version(self.env['MSVC_VERSION'])
@@ -1164,16 +1165,16 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
         self.file.write('\t<Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />\n')
         self.file.write('\t<ImportGroup Label="ExtensionSettings">\n')
         self.file.write('\t</ImportGroup>\n')
-        
+
         for kind in confkeys:
             variant = self.configs[kind].variant
             platform = self.configs[kind].platform
             self.file.write(V10DSPImportGroupCondition % locals())
-        
+
         self.file.write('\t<PropertyGroup Label="UserMacros" />\n')
         self.file.write('\t<PropertyGroup>\n')
         self.file.write('\t<_ProjectFileVersion>10.0.30319.1</_ProjectFileVersion>\n')
-        
+
         for kind in confkeys:
             variant = self.configs[kind].variant
             platform = self.configs[kind].platform
@@ -1181,7 +1182,7 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
             buildtarget = self.configs[kind].buildtarget
             runfile     = self.configs[kind].runfile
             cmdargs = self.configs[kind].cmdargs
-            
+
             env_has_buildtarget = 'MSVSBUILDTARGET' in self.env
             if not env_has_buildtarget:
                 self.env['MSVSBUILDTARGET'] = buildtarget
@@ -1206,29 +1207,29 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                 del self.env['MSVSBUILDTARGET']
 
             self.file.write(V10DSPCommandLine % locals())
-        
+
         self.file.write('\t</PropertyGroup>\n')
-        
+
         #filter settings in MSVS 2010 are stored in separate file
         self.filtersabs = self.dspabs + '.filters'
         try:
             self.filters_file = open(self.filtersabs, 'w')
-        except IOError, detail:
+        except IOError as detail:
             raise SCons.Errors.InternalError('Unable to open "' + self.filtersabs + '" for writing:' + str(detail))
-            
+
         self.filters_file.write('<?xml version="1.0" encoding="utf-8"?>\n'
                                 '<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">\n')
-                                
+
         self.PrintSourceFiles()
-        
+
         self.filters_file.write('</Project>')
         self.filters_file.close()
-        
+
         self.file.write('\t<Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />\n'
                         '\t<ImportGroup Label="ExtensionTargets">\n'
                         '\t</ImportGroup>\n'
                         '</Project>\n')
-                        
+
         if self.nokeep == 0:
             # now we pickle some data and add it to the file -- MSDEV will ignore it.
             pdata = pickle.dumps(self.configs,1)
@@ -1240,7 +1241,7 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
 
     def printFilters(self, hierarchy, name):
         sorteditems = sorted(hierarchy.items(), key = lambda a: a[0].lower())
-        
+
         for key, value in sorteditems:
             if SCons.Util.is_Dict(value):
                 filter_name = name + '\\' + key
@@ -1248,14 +1249,14 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                                         '\t\t\t<UniqueIdentifier>%s</UniqueIdentifier>\n'
                                         '\t\t</Filter>\n' % (filter_name, _generateGUID(self.dspabs, filter_name)))
                 self.printFilters(value, filter_name)
-        
+
     def printSources(self, hierarchy, kind, commonprefix, filter_name):
         keywords = {'Source Files': 'ClCompile',
                     'Header Files': 'ClInclude',
                     'Local Headers': 'ClInclude',
                     'Resource Files': 'None',
                     'Other Files': 'None'}
-                    
+
         sorteditems = sorted(hierarchy.items(), key = lambda a: a[0].lower())
 
         # First folders, then files
@@ -1269,7 +1270,7 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                 if commonprefix:
                     file = os.path.join(commonprefix, value)
                 file = os.path.normpath(file)
-                
+
                 self.file.write('\t\t<%s Include="%s" />\n' % (keywords[kind], file))
                 self.filters_file.write('\t\t<%s Include="%s">\n'
                                         '\t\t\t<Filter>%s</Filter>\n'
@@ -1281,10 +1282,10 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                       'Local Headers': 'h;hpp;hxx;hm;inl',
                       'Resource Files': 'r;rc;ico;cur;bmp;dlg;rc2;rct;bin;cnt;rtf;gif;jpg;jpeg;jpe',
                       'Other Files': ''}
-        
+
         cats = sorted([k for k in categories.keys() if self.sources[k]],
 		              key = lambda a: a.lower())
-        
+
         # print vcxproj.filters file first
         self.filters_file.write('\t<ItemGroup>\n')
         for kind in cats:
@@ -1292,7 +1293,7 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                                     '\t\t\t<UniqueIdentifier>{7b42d31d-d53c-4868-8b92-ca2bc9fc052f}</UniqueIdentifier>\n'
                                     '\t\t\t<Extensions>%s</Extensions>\n'
                                     '\t\t</Filter>\n' % (kind, categories[kind]))
-                                    
+
             # First remove any common prefix
             sources = self.sources[kind]
             commonprefix = None
@@ -1305,17 +1306,17 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                 # +1 because the filename starts after the separator
                 sources = [s[len(cp)+1:] for s in sources]
                 commonprefix = cp
-            
+
             hierarchy = makeHierarchy(sources)
             self.printFilters(hierarchy, kind)
-            
+
         self.filters_file.write('\t</ItemGroup>\n')
-            
+
         # then print files and filters
         for kind in cats:
             self.file.write('\t<ItemGroup>\n')
             self.filters_file.write('\t<ItemGroup>\n')
-                
+
             # First remove any common prefix
             sources = self.sources[kind]
             commonprefix = None
@@ -1328,13 +1329,13 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                 # +1 because the filename starts after the separator
                 sources = [s[len(cp)+1:] for s in sources]
                 commonprefix = cp
-            
+
             hierarchy = makeHierarchy(sources)
             self.printSources(hierarchy, kind, commonprefix, kind)
-                        
+
             self.file.write('\t</ItemGroup>\n')
             self.filters_file.write('\t</ItemGroup>\n')
-                
+
         # add the SConscript file outside of the groups
         self.file.write('\t<ItemGroup>\n'
                         '\t\t<None Include="%s" />\n'
@@ -1342,18 +1343,18 @@ class _GenerateV10DSP(_DSPGenerator, _GenerateV10User):
                         '\t</ItemGroup>\n' % str(self.sconscript))
 
     def Parse(self):
-        print "_GenerateV10DSP.Parse()"
+        print("_GenerateV10DSP.Parse()")
 
     def Build(self):
         try:
             self.file = open(self.dspabs, 'w')
-        except IOError, detail:
+        except IOError as detail:
             raise SCons.Errors.InternalError('Unable to open "' + self.dspabs + '" for writing:' + str(detail))
         else:
             self.PrintHeader()
             self.PrintProject()
             self.file.close()
-            
+
         _GenerateV10User.Build(self)
 
 class _DSWGenerator(object):
@@ -1428,7 +1429,7 @@ class _GenerateV7DSW(_DSWGenerator):
                 config.platform = 'Win32'
 
             self.configs[variant] = config
-            print "Adding '" + self.name + ' - ' + config.variant + '|' + config.platform + "' to '" + str(dswfile) + "'"
+            print("Adding '" + self.name + ' - ' + config.variant + '|' + config.platform + "' to '" + str(dswfile) + "'")
 
         if 'variant' not in env:
             raise SCons.Errors.InternalError("You must specify a 'variant' argument (i.e. 'Debug' or " +\
@@ -1461,7 +1462,7 @@ class _GenerateV7DSW(_DSWGenerator):
                                 'SLN_RELATIVE_FOLDER_PATH': dsp_relative_folder_path,
                                 'SLN_RELATIVE_FILE_PATH': dsp_relative_file_path}
                 self.dspfiles_info.append(dspfile_info)
-                
+
         self.dspfiles_info = []
         GenerateProjectFilesInfo(self)
 
@@ -1507,7 +1508,7 @@ class _GenerateV7DSW(_DSWGenerator):
             self.file.write('# Visual Studio 2008\n')
         elif self.version_num >= 8.0:
             self.file.write('# Visual Studio 2005\n')
-            
+
         for dspinfo in self.dspfiles_info:
             name = dspinfo['NAME']
             base, suffix = SCons.Util.splitext(name)
@@ -1612,7 +1613,7 @@ class _GenerateV7DSW(_DSWGenerator):
     def Build(self):
         try:
             self.file = open(self.dswfile,'w')
-        except IOError, detail:
+        except IOError as detail:
             raise SCons.Errors.InternalError('Unable to open "' + self.dswfile + '" for writing:' + str(detail))
         else:
             self.PrintSolution()
@@ -1661,7 +1662,7 @@ class _GenerateV6DSW(_DSWGenerator):
     def Build(self):
         try:
             self.file = open(self.dswfile,'w')
-        except IOError, detail:
+        except IOError as detail:
             raise SCons.Errors.InternalError('Unable to open "' + self.dswfile + '" for writing:' + str(detail))
         else:
             self.PrintWorkspace()
@@ -1718,8 +1719,8 @@ def GenerateProject(target, source, env):
     if not dspfile is builddspfile:
         try:
             bdsp = open(str(builddspfile), "w+")
-        except IOError, detail:
-            print 'Unable to open "' + str(dspfile) + '" for writing:',detail,'\n'
+        except IOError as detail:
+            print('Unable to open "' + str(dspfile) + '" for writing:',detail,'\n')
             raise
 
         bdsp.write("This is just a placeholder file.\nThe real project file is here:\n%s\n" % dspfile.get_abspath())
@@ -1734,8 +1735,8 @@ def GenerateProject(target, source, env):
 
             try:
                 bdsw = open(str(builddswfile), "w+")
-            except IOError, detail:
-                print 'Unable to open "' + str(dspfile) + '" for writing:',detail,'\n'
+            except IOError as detail:
+                print('Unable to open "' + str(dspfile) + '" for writing:',detail,'\n')
                 raise
 
             bdsw.write("This is just a placeholder file.\nThe real workspace file is here:\n%s\n" % dswfile.get_abspath())
@@ -1969,7 +1970,7 @@ def generate(env):
     else:
         env['MSVS']['PROJECTSUFFIX']  = '.vcxproj'
         env['MSVS']['SOLUTIONSUFFIX'] = '.sln'
-		
+
     if (version_num >= 10.0):
         env['MSVSENCODING'] = 'utf-8'
     else:
diff --git a/src/engine/SCons/Tool/msvsTests.py b/src/engine/SCons/Tool/msvsTests.py
index 261dbcc..2bd640f 100644
--- a/src/engine/SCons/Tool/msvsTests.py
+++ b/src/engine/SCons/Tool/msvsTests.py
@@ -20,6 +20,7 @@
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -827,7 +828,7 @@ if __name__ == "__main__":
     ]
 
     for test_class in test_classes:
-        print "TEST: ", test_class.__doc__
+        print("TEST: ", test_class.__doc__)
         back_osenv = copy.deepcopy(os.environ)
         try:
             # XXX: overriding the os.environ is bad, but doing it
diff --git a/src/engine/SCons/Tool/packaging/__init__.py b/src/engine/SCons/Tool/packaging/__init__.py
index 0f9a93d..1a95abe 100644
--- a/src/engine/SCons/Tool/packaging/__init__.py
+++ b/src/engine/SCons/Tool/packaging/__init__.py
@@ -119,7 +119,7 @@ def Package(env, target=None, source=None, **kw):
         try:
             file,path,desc=imp.find_module(type, __path__)
             return imp.load_module(type, file, path, desc)
-        except ImportError, e:
+        except ImportError as e:
             raise EnvironmentError("packager %s not available: %s"%(type,str(e)))
 
     packagers=list(map(load_packager, PACKAGETYPE))
@@ -140,7 +140,7 @@ def Package(env, target=None, source=None, **kw):
         if 'PACKAGEROOT' not in kw:
             kw['PACKAGEROOT'] = default_name%kw
 
-    except KeyError, e:
+    except KeyError as e:
         raise SCons.Errors.UserError( "Missing Packagetag '%s'"%e.args[0] )
 
     # setup the source files
@@ -156,10 +156,10 @@ def Package(env, target=None, source=None, **kw):
 
         assert( len(target) == 0 )
 
-    except KeyError, e:
+    except KeyError as e:
         raise SCons.Errors.UserError( "Missing Packagetag '%s' for %s packager"\
                                       % (e.args[0],packager.__name__) )
-    except TypeError, e:
+    except TypeError as e:
         # this exception means that a needed argument for the packager is
         # missing. As our packagers get their "tags" as named function
         # arguments we need to find out which one is missing.
diff --git a/src/engine/SCons/Tool/packaging/msi.py b/src/engine/SCons/Tool/packaging/msi.py
index 41b7ab7..c25f856 100644
--- a/src/engine/SCons/Tool/packaging/msi.py
+++ b/src/engine/SCons/Tool/packaging/msi.py
@@ -216,7 +216,7 @@ def build_wxsfile(target, source, env):
         if 'CHANGE_SPECFILE' in env:
             env['CHANGE_SPECFILE'](target, source)
 
-    except KeyError, e:
+    except KeyError as e:
         raise SCons.Errors.UserError( '"%s" package field for MSI is missing.' % e.args[0] )
 
 #
diff --git a/src/engine/SCons/Tool/packaging/rpm.py b/src/engine/SCons/Tool/packaging/rpm.py
index e5d2f0b..eac3c43 100644
--- a/src/engine/SCons/Tool/packaging/rpm.py
+++ b/src/engine/SCons/Tool/packaging/rpm.py
@@ -101,7 +101,7 @@ def collectintargz(target, source, env):
     tarball = (str(target[0])+".tar.gz").replace('.rpm', '')
     try:
         tarball = env['SOURCE_URL'].split('/')[-1]
-    except KeyError, e:
+    except KeyError as e:
         raise SCons.Errors.UserError( "Missing PackageTag '%s' for RPM packager" % e.args[0] )
 
     tarball = src_targz.package(env, source=sources, target=tarball,
@@ -136,7 +136,7 @@ def build_specfile(target, source, env):
         if 'CHANGE_SPECFILE' in env:
             env['CHANGE_SPECFILE'](target, source)
 
-    except KeyError, e:
+    except KeyError as e:
         raise SCons.Errors.UserError( '"%s" package field for RPM is missing.' % e.args[0] )
 
 
@@ -323,7 +323,7 @@ class SimpleTagCompiler(object):
         for key, replacement in domestic:
             try:
                 str = str + replacement % values[key]
-            except KeyError, e:
+            except KeyError as e:
                 if self.mandatory:
                     raise e
 
@@ -334,7 +334,7 @@ class SimpleTagCompiler(object):
                 int_values_for_key = [(get_country_code(t[0]),t[1]) for t in x]
                 for v in int_values_for_key:
                     str = str + replacement % v
-            except KeyError, e:
+            except KeyError as e:
                 if self.mandatory:
                     raise e
 
diff --git a/src/engine/SCons/Tool/pdflatex.py b/src/engine/SCons/Tool/pdflatex.py
index 922e718..fbffb23 100644
--- a/src/engine/SCons/Tool/pdflatex.py
+++ b/src/engine/SCons/Tool/pdflatex.py
@@ -62,7 +62,7 @@ def generate(env):
 
     env.AppendUnique(LATEXSUFFIXES=SCons.Tool.LaTeXSuffixes)
 
-    import pdf
+    from . import pdf
     pdf.generate(env)
 
     bld = env['BUILDERS']['PDF']
diff --git a/src/engine/SCons/Tool/pdftex.py b/src/engine/SCons/Tool/pdftex.py
index 30c56af..e9a0bda 100644
--- a/src/engine/SCons/Tool/pdftex.py
+++ b/src/engine/SCons/Tool/pdftex.py
@@ -85,7 +85,7 @@ def generate(env):
 
     env.AppendUnique(LATEXSUFFIXES=SCons.Tool.LaTeXSuffixes)
 
-    import pdf
+    from . import pdf
     pdf.generate(env)
 
     bld = env['BUILDERS']['PDF']
diff --git a/src/engine/SCons/Tool/qt.py b/src/engine/SCons/Tool/qt.py
index 7bc0ef6..f01fff6 100644
--- a/src/engine/SCons/Tool/qt.py
+++ b/src/engine/SCons/Tool/qt.py
@@ -31,6 +31,7 @@ selection method.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -130,12 +131,12 @@ class _Automoc(object):
             if not obj.has_builder():
                 # binary obj file provided
                 if debug:
-                    print "scons: qt: '%s' seems to be a binary. Discarded." % str(obj)
+                    print("scons: qt: '%s' seems to be a binary. Discarded." % str(obj))
                 continue
             cpp = obj.sources[0]
             if not splitext(str(cpp))[1] in cxx_suffixes:
                 if debug:
-                    print "scons: qt: '%s' is no cxx file. Discarded." % str(cpp) 
+                    print("scons: qt: '%s' is no cxx file. Discarded." % str(cpp)) 
                 # c or fortran source
                 continue
             #cpp_contents = comment.sub('', cpp.get_text_contents())
@@ -148,12 +149,12 @@ class _Automoc(object):
                 h = find_file(hname, (cpp.get_dir(),), env.File)
                 if h:
                     if debug:
-                        print "scons: qt: Scanning '%s' (header of '%s')" % (str(h), str(cpp))
+                        print("scons: qt: Scanning '%s' (header of '%s')" % (str(h), str(cpp)))
                     #h_contents = comment.sub('', h.get_text_contents())
                     h_contents = h.get_text_contents()
                     break
             if not h and debug:
-                print "scons: qt: no header for '%s'." % (str(cpp))
+                print("scons: qt: no header for '%s'." % (str(cpp)))
             if h and q_object_search.search(h_contents):
                 # h file with the Q_OBJECT macro found -> add moc_cpp
                 moc_cpp = env.Moc(h)
@@ -161,14 +162,14 @@ class _Automoc(object):
                 out_sources.append(moc_o)
                 #moc_cpp.target_scanner = SCons.Defaults.CScan
                 if debug:
-                    print "scons: qt: found Q_OBJECT macro in '%s', moc'ing to '%s'" % (str(h), str(moc_cpp))
+                    print("scons: qt: found Q_OBJECT macro in '%s', moc'ing to '%s'" % (str(h), str(moc_cpp)))
             if cpp and q_object_search.search(cpp_contents):
                 # cpp file with Q_OBJECT macro found -> add moc
                 # (to be included in cpp)
                 moc = env.Moc(cpp)
                 env.Ignore(moc, moc)
                 if debug:
-                    print "scons: qt: found Q_OBJECT macro in '%s', moc'ing to '%s'" % (str(cpp), str(moc))
+                    print("scons: qt: found Q_OBJECT macro in '%s', moc'ing to '%s'" % (str(cpp), str(moc)))
                 #moc.source_scanner = SCons.Defaults.CScan
         # restore the original env attributes (FIXME)
         objBuilder.env = objBuilderEnv
diff --git a/src/engine/SCons/Tool/rpmutils.py b/src/engine/SCons/Tool/rpmutils.py
index e20d53b..3eeed1d 100644
--- a/src/engine/SCons/Tool/rpmutils.py
+++ b/src/engine/SCons/Tool/rpmutils.py
@@ -34,6 +34,7 @@ exact syntax.
 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -501,7 +502,7 @@ def updateRpmDicts(rpmrc, pyfile):
                 key = tokens[0]
                 if key in sections:
                     # Have we met this section before?
-                    if not data.has_key(tokens[0]):
+                    if tokens[0] not in data:
                         # No, so insert it
                         data[key] = {}
                     # Insert data
@@ -519,7 +520,7 @@ def updateRpmDicts(rpmrc, pyfile):
                 if l.startswith('# Start of rpmrc dictionaries'):
                     pm = 1
                     # Write data sections to single dictionaries
-                    for key, entries in data.iteritems():
+                    for key, entries in data.items():
                         out.write("%s = {\n" % key)
                         for arch in sorted(entries.keys()):
                             out.write("  '%s' : ['%s'],\n" % (arch, "','".join(entries[arch])))
@@ -529,7 +530,7 @@ def updateRpmDicts(rpmrc, pyfile):
         pass
 
 def usage():
-    print "rpmutils.py rpmrc.in rpmutils.py"
+    print("rpmutils.py rpmrc.in rpmutils.py")
 
 def main():
     import sys
diff --git a/src/engine/SCons/Tool/sgicc.py b/src/engine/SCons/Tool/sgicc.py
index 662eb7d..94a0497 100644
--- a/src/engine/SCons/Tool/sgicc.py
+++ b/src/engine/SCons/Tool/sgicc.py
@@ -33,7 +33,7 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import cc
+from . import cc
 
 def generate(env):
     """Add Builders and construction variables for gcc to an Environment."""
diff --git a/src/engine/SCons/Tool/sgilink.py b/src/engine/SCons/Tool/sgilink.py
index 6244141..b1e7921 100644
--- a/src/engine/SCons/Tool/sgilink.py
+++ b/src/engine/SCons/Tool/sgilink.py
@@ -35,7 +35,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
-import link
+from . import link
 
 linkers = ['CC', 'cc']
 
diff --git a/src/engine/SCons/Tool/suncc.py b/src/engine/SCons/Tool/suncc.py
index 458538b..4651219 100644
--- a/src/engine/SCons/Tool/suncc.py
+++ b/src/engine/SCons/Tool/suncc.py
@@ -34,7 +34,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
-import cc
+from . import cc
 
 def generate(env):
     """
diff --git a/src/engine/SCons/Tool/sunf77.py b/src/engine/SCons/Tool/sunf77.py
index d05ce54..20d1893 100644
--- a/src/engine/SCons/Tool/sunf77.py
+++ b/src/engine/SCons/Tool/sunf77.py
@@ -35,7 +35,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
-from FortranCommon import add_all_to_env
+from .FortranCommon import add_all_to_env
 
 compilers = ['sunf77', 'f77']
 
diff --git a/src/engine/SCons/Tool/sunf90.py b/src/engine/SCons/Tool/sunf90.py
index 93b89c0..ce1697c 100644
--- a/src/engine/SCons/Tool/sunf90.py
+++ b/src/engine/SCons/Tool/sunf90.py
@@ -35,7 +35,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
-from FortranCommon import add_all_to_env
+from .FortranCommon import add_all_to_env
 
 compilers = ['sunf90', 'f90']
 
diff --git a/src/engine/SCons/Tool/sunf95.py b/src/engine/SCons/Tool/sunf95.py
index c09026c..218569c 100644
--- a/src/engine/SCons/Tool/sunf95.py
+++ b/src/engine/SCons/Tool/sunf95.py
@@ -35,7 +35,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import SCons.Util
 
-from FortranCommon import add_all_to_env
+from .FortranCommon import add_all_to_env
 
 compilers = ['sunf95', 'f95']
 
diff --git a/src/engine/SCons/Tool/sunlink.py b/src/engine/SCons/Tool/sunlink.py
index 680af03..39d9ec2 100644
--- a/src/engine/SCons/Tool/sunlink.py
+++ b/src/engine/SCons/Tool/sunlink.py
@@ -37,7 +37,7 @@ import os.path
 
 import SCons.Util
 
-import link
+from . import link
 
 ccLinker = None
 
diff --git a/src/engine/SCons/Tool/swig.py b/src/engine/SCons/Tool/swig.py
index 3a5a3cc..fa86174 100644
--- a/src/engine/SCons/Tool/swig.py
+++ b/src/engine/SCons/Tool/swig.py
@@ -7,6 +7,7 @@ It will usually be imported through the generic SCons.Tool.Tool()
 selection method.
 
 """
+from __future__ import print_function
 
 #
 # __COPYRIGHT__
@@ -140,13 +141,14 @@ def _get_swig_version(env, swig):
                                  stdout = subprocess.PIPE)
     if pipe.wait() != 0: return
 
+    # MAYBE:   out = SCons.Util.to_str (pipe.stdout.read())
     out = pipe.stdout.read()
     match = re.search(r'SWIG Version\s+(\S+).*', out, re.MULTILINE)
     if match:
-        if verbose: print "Version is:%s"%match.group(1)
+        if verbose: print("Version is:%s"%match.group(1))
         return match.group(1)
     else:
-        if verbose: print "Unable to detect version: [%s]"%out
+        if verbose: print("Unable to detect version: [%s]"%out)
 
 def generate(env):
     """Add Builders and construction variables for swig to an Environment."""
diff --git a/src/engine/SCons/Tool/tex.py b/src/engine/SCons/Tool/tex.py
index 3d429c9..85bd41f 100644
--- a/src/engine/SCons/Tool/tex.py
+++ b/src/engine/SCons/Tool/tex.py
@@ -31,6 +31,7 @@ selection method.
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
+from __future__ import print_function
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
@@ -164,15 +165,15 @@ def FindFile(name,suffixes,paths,env,requireExt=False):
         if ext:
             name = name + ext
     if Verbose:
-        print " searching for '%s' with extensions: " % name,suffixes
+        print(" searching for '%s' with extensions: " % name,suffixes)
 
     for path in paths:
         testName = os.path.join(path,name)
         if Verbose:
-            print " look for '%s'" % testName
+            print(" look for '%s'" % testName)
         if os.path.isfile(testName):
             if Verbose:
-                print " found '%s'" % testName
+                print(" found '%s'" % testName)
             return env.fs.File(testName)
         else:
             name_ext = SCons.Util.splitext(testName)[1]
@@ -183,14 +184,14 @@ def FindFile(name,suffixes,paths,env,requireExt=False):
             for suffix in suffixes:
                 testNameExt = testName + suffix
                 if Verbose:
-                    print " look for '%s'" % testNameExt
+                    print(" look for '%s'" % testNameExt)
 
                 if os.path.isfile(testNameExt):
                     if Verbose:
-                        print " found '%s'" % testNameExt
+                        print(" found '%s'" % testNameExt)
                     return env.fs.File(testNameExt)
     if Verbose:
-        print " did not find '%s'" % name
+        print(" did not find '%s'" % name)
     return None
 
 def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None):
@@ -250,7 +251,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
         saved_hashes[suffix] = theNode.get_csig()
 
     if Verbose:
-        print "hashes: ",saved_hashes
+        print("hashes: ",saved_hashes)
 
     must_rerun_latex = True
 
@@ -269,12 +270,12 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
 
         if saved_hashes[suffix] == new_md5:
             if Verbose:
-                print "file %s not changed" % (targetbase+suffix)
+                print("file %s not changed" % (targetbase+suffix))
             return False        # unchanged
         saved_hashes[suffix] = new_md5
         must_rerun_latex = True
         if Verbose:
-            print "file %s changed, rerunning Latex, new hash = " % (targetbase+suffix), new_md5
+            print("file %s changed, rerunning Latex, new hash = " % (targetbase+suffix), new_md5)
         return True     # changed
 
     # generate the file name that latex will generate
@@ -323,8 +324,8 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
             bcffiles = list(dups.keys())
 
         if Verbose:
-            print "auxfiles ",auxfiles
-            print "bcffiles ",bcffiles
+            print("auxfiles ",auxfiles)
+            print("bcffiles ",bcffiles)
 
         # Now decide if bibtex will need to be run.
         # The information that bibtex reads from the .aux file is
@@ -340,7 +341,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
                     content = open(target_aux, "rb").read()
                     if content.find("bibdata") != -1:
                         if Verbose:
-                            print "Need to run bibtex on ",auxfilename
+                            print("Need to run bibtex on ",auxfilename)
                         bibfile = env.fs.File(SCons.Util.splitext(target_aux)[0])
                         result = BibTeXAction(bibfile, bibfile, env)
                         if result != 0:
@@ -363,7 +364,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
                     content = open(target_bcf, "rb").read()
                     if content.find("bibdata") != -1:
                         if Verbose:
-                            print "Need to run biber on ",bcffilename
+                            print("Need to run biber on ",bcffilename)
                         bibfile = env.fs.File(SCons.Util.splitext(target_bcf)[0])
                         result = BiberAction(bibfile, bibfile, env)
                         if result != 0:
@@ -374,7 +375,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
         if check_MD5(suffix_nodes['.idx'],'.idx') or (count == 1 and run_makeindex):
             # We must run makeindex
             if Verbose:
-                print "Need to run makeindex"
+                print("Need to run makeindex")
             idxfile = suffix_nodes['.idx']
             result = MakeIndexAction(idxfile, idxfile, env)
             if result != 0:
@@ -392,7 +393,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
         if check_MD5(suffix_nodes['.nlo'],'.nlo') or (count == 1 and run_nomenclature):
             # We must run makeindex
             if Verbose:
-                print "Need to run makeindex for nomenclature"
+                print("Need to run makeindex for nomenclature")
             nclfile = suffix_nodes['.nlo']
             result = MakeNclAction(nclfile, nclfile, env)
             if result != 0:
@@ -404,7 +405,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
         if check_MD5(suffix_nodes['.glo'],'.glo') or (count == 1 and run_glossaries) or (count == 1 and run_glossary):
             # We must run makeindex
             if Verbose:
-                print "Need to run makeindex for glossary"
+                print("Need to run makeindex for glossary")
             glofile = suffix_nodes['.glo']
             result = MakeGlossaryAction(glofile, glofile, env)
             if result != 0:
@@ -416,7 +417,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
         if check_MD5(suffix_nodes['.acn'],'.acn') or (count == 1 and run_acronyms):
             # We must run makeindex
             if Verbose:
-                print "Need to run makeindex for acronyms"
+                print("Need to run makeindex for acronyms")
             acrfile = suffix_nodes['.acn']
             result = MakeAcronymsAction(acrfile, acrfile, env)
             if result != 0:
@@ -429,7 +430,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
             if check_MD5(suffix_nodes[newglossary_suffix[ig][2]],newglossary_suffix[ig][2]) or (count == 1):
                 # We must run makeindex
                 if Verbose:
-                    print "Need to run makeindex for newglossary"
+                    print("Need to run makeindex for newglossary")
                 newglfile = suffix_nodes[newglossary_suffix[ig][2]]
                 MakeNewGlossaryAction = SCons.Action.Action("$MAKENEWGLOSSARYCOM ${SOURCE.filebase}%s -s ${SOURCE.filebase}.ist -t ${SOURCE.filebase}%s -o ${SOURCE.filebase}%s" % (newglossary_suffix[ig][2],newglossary_suffix[ig][0],newglossary_suffix[ig][1]), "$MAKENEWGLOSSARYCOMSTR")
 
@@ -443,26 +444,26 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
         if warning_rerun_re.search(logContent):
             must_rerun_latex = True
             if Verbose:
-                print "rerun Latex due to latex or package rerun warning"
+                print("rerun Latex due to latex or package rerun warning")
 
         if rerun_citations_re.search(logContent):
             must_rerun_latex = True
             if Verbose:
-                print "rerun Latex due to 'Rerun to get citations correct' warning"
+                print("rerun Latex due to 'Rerun to get citations correct' warning")
 
         if undefined_references_re.search(logContent):
             must_rerun_latex = True
             if Verbose:
-                print "rerun Latex due to undefined references or citations"
+                print("rerun Latex due to undefined references or citations")
 
         if (count >= int(env.subst('$LATEXRETRIES')) and must_rerun_latex):
-            print "reached max number of retries on Latex ,",int(env.subst('$LATEXRETRIES'))
+            print("reached max number of retries on Latex ,",int(env.subst('$LATEXRETRIES')))
 # end of while loop
 
     # rename Latex's output to what the target name is
     if not (str(target[0]) == resultfilename  and  os.path.isfile(resultfilename)):
         if os.path.isfile(resultfilename):
-            print "move %s to %s" % (resultfilename, str(target[0]), )
+            print("move %s to %s" % (resultfilename, str(target[0]), ))
             shutil.move(resultfilename,str(target[0]))
 
     # Original comment (when TEXPICTS was not restored):
@@ -516,27 +517,27 @@ def is_LaTeX(flist,env,abspath):
     else:
         env['ENV']['TEXINPUTS'] = savedpath
     if Verbose:
-        print "is_LaTeX search path ",paths
-        print "files to search :",flist
+        print("is_LaTeX search path ",paths)
+        print("files to search :",flist)
 
     # Now that we have the search path and file list, check each one
     for f in flist:
         if Verbose:
-            print " checking for Latex source ",str(f)
+            print(" checking for Latex source ",str(f))
 
         content = f.get_text_contents()
         if LaTeX_re.search(content):
             if Verbose:
-                print "file %s is a LaTeX file" % str(f)
+                print("file %s is a LaTeX file" % str(f))
             return 1
         if Verbose:
-            print "file %s is not a LaTeX file" % str(f)
+            print("file %s is not a LaTeX file" % str(f))
 
         # now find included files
         inc_files = [ ]
         inc_files.extend( include_re.findall(content) )
         if Verbose:
-            print "files included by '%s': "%str(f),inc_files
+            print("files included by '%s': "%str(f),inc_files)
         # inc_files is list of file names as given. need to find them
         # using TEXINPUTS paths.
 
@@ -546,7 +547,7 @@ def is_LaTeX(flist,env,abspath):
             # make this a list since is_LaTeX takes a list.
             fileList = [srcNode,]
             if Verbose:
-                print "FindFile found ",srcNode
+                print("FindFile found ",srcNode)
             if srcNode is not None:
                 file_test = is_LaTeX(fileList, env, abspath)
 
@@ -555,7 +556,7 @@ def is_LaTeX(flist,env,abspath):
                 return file_test
 
         if Verbose:
-            print " done scanning ",str(f)
+            print(" done scanning ",str(f))
 
     return 0
 
@@ -620,15 +621,15 @@ def ScanFiles(theFile, target, paths, file_tests, file_tests_search, env, graphi
 
     content = theFile.get_text_contents()
     if Verbose:
-        print " scanning ",str(theFile)
+        print(" scanning ",str(theFile))
 
     for i in range(len(file_tests_search)):
         if file_tests[i][0] is None:
             if Verbose:
-                print "scan i ",i," files_tests[i] ",file_tests[i], file_tests[i][1]
+                print("scan i ",i," files_tests[i] ",file_tests[i], file_tests[i][1])
             file_tests[i][0] = file_tests_search[i].search(content)
             if Verbose and file_tests[i][0]:
-                print "   found match for ",file_tests[i][1][-1]
+                print("   found match for ",file_tests[i][1][-1])
             # for newglossary insert the suffixes in file_tests[i]
             if file_tests[i][0] and file_tests[i][1][-1] == 'newglossary':
                 findresult = file_tests_search[i].findall(content)
@@ -639,19 +640,19 @@ def ScanFiles(theFile, target, paths, file_tests, file_tests_search, env, graphi
                     suffix_list = ['.'+findresult[l][0],'.'+findresult[l][2],'.'+findresult[l][3] ]
                     newglossary_suffix.append(suffix_list)
                 if Verbose:
-                    print " new suffixes for newglossary ",newglossary_suffix
-                
+                    print(" new suffixes for newglossary ",newglossary_suffix)
+
 
     incResult = includeOnly_re.search(content)
     if incResult:
         aux_files.append(os.path.join(targetdir, incResult.group(1)))
     if Verbose:
-        print "\include file names : ", aux_files
+        print("\include file names : ", aux_files)
     # recursively call this on each of the included files
     inc_files = [ ]
     inc_files.extend( include_re.findall(content) )
     if Verbose:
-        print "files included by '%s': "%str(theFile),inc_files
+        print("files included by '%s': "%str(theFile),inc_files)
     # inc_files is list of file names as given. need to find them
     # using TEXINPUTS paths.
 
@@ -660,7 +661,7 @@ def ScanFiles(theFile, target, paths, file_tests, file_tests_search, env, graphi
         if srcNode is not None:
             file_tests = ScanFiles(srcNode, target, paths, file_tests, file_tests_search, env, graphics_extensions, targetdir, aux_files)
     if Verbose:
-        print " done scanning ",str(theFile)
+        print(" done scanning ",str(theFile))
     return file_tests
 
 def tex_emitter_core(target, source, env, graphics_extensions):
@@ -692,7 +693,7 @@ def tex_emitter_core(target, source, env, graphics_extensions):
     env.SideEffect(flsfilename,target[0])
     env.SideEffect(syncfilename,target[0])
     if Verbose:
-        print "side effect :",auxfilename,logfilename,flsfilename,syncfilename
+        print("side effect :",auxfilename,logfilename,flsfilename,syncfilename)
     env.Clean(target[0],auxfilename)
     env.Clean(target[0],logfilename)
     env.Clean(target[0],flsfilename)
@@ -765,7 +766,7 @@ def tex_emitter_core(target, source, env, graphics_extensions):
     else:
         env['ENV']['TEXINPUTS'] = savedpath
     if Verbose:
-        print "search path ",paths
+        print("search path ",paths)
 
     # scan all sources for side effect files
     aux_files = []
@@ -774,7 +775,7 @@ def tex_emitter_core(target, source, env, graphics_extensions):
     for (theSearch,suffix_list) in file_tests:
         # add side effects if feature is present.If file is to be generated,add all side effects
         if Verbose and theSearch:
-            print "check side effects for ",suffix_list[-1]
+            print("check side effects for ",suffix_list[-1])
         if (theSearch != None) or (not source[0].exists() ):
             file_list = [targetbase,]
             # for bibunit we need a list of files
@@ -788,11 +789,11 @@ def tex_emitter_core(target, source, env, graphics_extensions):
             if suffix_list[-1] == 'multibib':
                 for multibibmatch in multibib_re.finditer(content):
                     if Verbose:
-                        print "multibib match ",multibibmatch.group(1)
+                        print("multibib match ",multibibmatch.group(1))
                     if multibibmatch != None:
                         baselist = multibibmatch.group(1).split(',')
                         if Verbose:
-                            print "multibib list ", baselist
+                            print("multibib list ", baselist)
                         for i in range(len(baselist)):
                             file_list.append(os.path.join(targetdir, baselist[i]))
             # now define the side effects
@@ -800,14 +801,14 @@ def tex_emitter_core(target, source, env, graphics_extensions):
                 for suffix in suffix_list[:-1]:
                     env.SideEffect(file_name + suffix,target[0])
                     if Verbose:
-                        print "side effect tst :",file_name + suffix, " target is ",str(target[0])
+                        print("side effect tst :",file_name + suffix, " target is ",str(target[0]))
                     env.Clean(target[0],file_name + suffix)
 
     for aFile in aux_files:
         aFile_base = SCons.Util.splitext(aFile)[0]
         env.SideEffect(aFile_base + '.aux',target[0])
         if Verbose:
-            print "side effect aux :",aFile_base + '.aux'
+            print("side effect aux :",aFile_base + '.aux')
         env.Clean(target[0],aFile_base + '.aux')
     # read fls file to get all other files that latex creates and will read on the next pass
     # remove files from list that we explicitly dealt with above
@@ -820,7 +821,7 @@ def tex_emitter_core(target, source, env, graphics_extensions):
                 out_files.remove(filename)
         env.SideEffect(out_files,target[0])
         if Verbose:
-            print "side effect fls :",out_files
+            print("side effect fls :",out_files)
         env.Clean(target[0],out_files)
 
     return (target, source)
@@ -840,7 +841,7 @@ def generate(env):
 
     generate_common(env)
 
-    import dvi
+    from . import dvi
     dvi.generate(env)
 
     bld = env['BUILDERS']['DVI']
@@ -853,7 +854,7 @@ def generate_darwin(env):
     except KeyError:
         environ = {}
         env['ENV'] = environ
-    
+
     if (platform.system() == 'Darwin'):
         try:
             ospath = env['ENV']['PATHOSX']
diff --git a/src/engine/SCons/Tool/textfile.py b/src/engine/SCons/Tool/textfile.py
index 76efbd7..e79badf 100644
--- a/src/engine/SCons/Tool/textfile.py
+++ b/src/engine/SCons/Tool/textfile.py
@@ -107,7 +107,7 @@ def _action(target, source, env):
     # write the file
     try:
         fd = open(target[0].get_path(), "wb")
-    except (OSError,IOError), e:
+    except (OSError,IOError) as e:
         raise SCons.Errors.UserError("Can't write target file %s" % target[0])
     # separate lines by 'linesep' only if linesep is not empty
     lsep = None
diff --git a/src/engine/SCons/Tool/xgettext.py b/src/engine/SCons/Tool/xgettext.py
index b8a88dc..e9b49b7 100644
--- a/src/engine/SCons/Tool/xgettext.py
+++ b/src/engine/SCons/Tool/xgettext.py
@@ -1,10 +1,10 @@
-""" xgettext tool 
+""" xgettext tool
 
 Tool specific initialization of `xgettext` tool.
 """
 
 # __COPYRIGHT__
-# 
+#
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
 # "Software"), to deal in the Software without restriction, including
@@ -12,10 +12,10 @@ Tool specific initialization of `xgettext` tool.
 # distribute, sublicense, and/or sell copies of the Software, and to
 # permit persons to whom the Software is furnished to do so, subject to
 # the following conditions:
-# 
+#
 # The above copyright notice and this permission notice shall be included
 # in all copies or substantial portions of the Software.
-# 
+#
 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
 # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
@@ -32,19 +32,19 @@ class _CmdRunner(object):
   variables. It also provides `strfunction()` method, which shall be used by
   scons Action objects to print command string. """
 
-  def __init__( self, command, commandstr = None):
+  def __init__(self, command, commandstr = None):
     self.out = None
     self.err = None
     self.status = None
     self.command = command
     self.commandstr = commandstr
 
-  def __call__(self, target, source, env): 
+  def __call__(self, target, source, env):
     import SCons.Action
     import subprocess
     import os
     import sys
-    kw = { 
+    kw = {
       'stdin'  : 'devnull',
       'stdout' : subprocess.PIPE,
       'stderr' : subprocess.PIPE,
@@ -55,7 +55,8 @@ class _CmdRunner(object):
     proc = SCons.Action._subproc(env, command, **kw)
     self.out, self.err = proc.communicate()
     self.status = proc.wait()
-    if self.err: sys.stderr.write(unicode(self.err))
+    if self.err:
+      sys.stderr.write(unicode(self.err))
     return self.status
 
   def strfunction(self, target, source, env):
@@ -104,9 +105,9 @@ def _update_pot_file(target, source, env):
   os.chdir(save_os_cwd)
   # If the command was not successfull, return error code.
   if status: return status
- 
+
   new_content = cmd.out
- 
+
   if not new_content:
     # When xgettext finds no internationalized messages, no *.pot is created
     # (because we don't want to bother translators with empty POT files).
@@ -144,7 +145,7 @@ def _update_pot_file(target, source, env):
     # Print message employing SCons.Action.Action for that.
     msg = "Not writing " + repr(str(target[0])) + " (" + explain + ")"
     env.Execute(SCons.Action.Action(nop, msg))
-    return 0 
+    return 0
 #############################################################################
 
 #############################################################################
@@ -153,7 +154,7 @@ from SCons.Builder import BuilderBase
 class _POTBuilder(BuilderBase):
   def _execute(self, env, target, source, *args):
     if not target:
-      if env.has_key('POTDOMAIN') and env['POTDOMAIN']:
+      if 'POTDOMAIN' in env and env['POTDOMAIN']:
         domain = env['POTDOMAIN']
       else:
         domain = 'messages'
@@ -175,7 +176,7 @@ def _scan_xgettext_from_files(target, source, env, files = None, path = None):
     files = [ files ]
 
   if path is None:
-    if env.has_key('XGETTEXTPATH'):
+    if 'XGETTEXTPATH' in env:
       path = env['XGETTEXTPATH']
     else:
       path = []
@@ -207,7 +208,7 @@ def _scan_xgettext_from_files(target, source, env, files = None, path = None):
       contents = re_emptyln.sub("", contents)
       contents = re_trailws.sub("", contents)
       depnames = contents.splitlines()
-      for depname in depnames: 
+      for depname in depnames:
         depfile = SCons.Node.FS.find_file(depname, dirs)
         if not depfile:
           depfile = env.arg2nodes(depname, dirs[0].File)
@@ -222,7 +223,7 @@ def _pot_update_emitter(target, source, env):
   import SCons.Util
   import SCons.Node.FS
 
-  if env.has_key('XGETTEXTFROM'): 
+  if 'XGETTEXTFROM' in env:
     xfrom = env['XGETTEXTFROM']
   else:
     return target, source
@@ -230,13 +231,13 @@ def _pot_update_emitter(target, source, env):
     xfrom = [ xfrom ]
 
   xfrom = SCons.Util.flatten(xfrom)
-  
+
   # Prepare list of 'POTFILE.in' files.
   files = []
   for xf in xfrom:
     if not isinstance(xf, SCons.Node.FS.Base):
       if SCons.Util.is_String(xf):
-        # Interpolate variables in strings 
+        # Interpolate variables in strings
         xf = env.subst(xf, source = source, target = target)
       xf = env.arg2nodes(xf)
     files.extend(xf)
@@ -274,7 +275,7 @@ def generate(env,**kw):
   try:
     env['XGETTEXT'] = _detect_xgettext(env)
   except:
-    env['XGETTEXT'] = 'xgettext' 
+    env['XGETTEXT'] = 'xgettext'
   # NOTE: sources="$SOURCES" would work as well. However, we use following
   # construction to convert absolute paths provided by scons onto paths
   # relative to current working dir. Note, that scons expands $SOURCE(S) to
diff --git a/src/engine/SCons/Util.py b/src/engine/SCons/Util.py
index 7bcd6e2..0be6196 100644
--- a/src/engine/SCons/Util.py
+++ b/src/engine/SCons/Util.py
@@ -32,16 +32,36 @@ import copy
 import re
 import types
 
-from collections import UserDict, UserList, UserString
+try:
+    from UserDict import UserDict
+except ImportError as e:
+    from collections import UserDict
+
+try:
+    from UserList import UserList
+except ImportError as e:
+    from collections import UserList
+
+try:
+    from UserString import UserString
+except ImportError as e:
+    from collections import UserString
 
 # Don't "from types import ..." these because we need to get at the
 # types module later to look for UnicodeType.
-InstanceType    = types.InstanceType
+
+# Below not used?
+# InstanceType    = types.InstanceType
+
 MethodType      = types.MethodType
 FunctionType    = types.FunctionType
-try: unicode
-except NameError: UnicodeType = None
-else:             UnicodeType = unicode
+
+try:
+    unicode
+except NameError:
+    UnicodeType = str
+else:
+    UnicodeType = unicode
 
 def dictify(keys, values, result={}):
     for k, v in zip(keys, values):
@@ -114,6 +134,9 @@ class NodeList(UserList):
     def __nonzero__(self):
         return len(self.data) != 0
 
+    def __bool__(self):
+        return self.__nonzero__()
+
     def __str__(self):
         return ' '.join(map(str, self.data))
 
@@ -153,7 +176,7 @@ class DisplayEngine(object):
             return
         if append_newline: text = text + '\n'
         try:
-            sys.stdout.write(unicode(text))
+            sys.stdout.write(UnicodeType(text))
         except IOError:
             # Stdout might be connected to a pipe that has been closed
             # by now. The most likely reason for the pipe being closed
@@ -228,7 +251,7 @@ def print_tree(root, child_func, prune=0, showtags=0, margin=[0], visited=None):
     """
 
     rname = str(root)
-    
+
     # Initialize 'visited' dict, if required
     if visited is None:
         visited = {}
@@ -311,11 +334,17 @@ SequenceTypes = (list, tuple, UserList)
 # Note that profiling data shows a speed-up when comparing
 # explicitly with str and unicode instead of simply comparing
 # with basestring. (at least on Python 2.5.1)
-StringTypes = (str, unicode, UserString)
+try:
+    StringTypes = (str, unicode, UserString)
+except NameError:
+    StringTypes = (str, UserString)
 
 # Empirically, it is faster to check explicitly for str and
 # unicode than for basestring.
-BaseStringTypes = (str, unicode)
+try:
+    BaseStringTypes = (str, unicode)
+except NameError:
+    BaseStringTypes = (str)
 
 def is_Dict(obj, isinstance=isinstance, DictTypes=DictTypes):
     return isinstance(obj, DictTypes)
@@ -341,7 +370,7 @@ def is_Scalar(obj, isinstance=isinstance, StringTypes=StringTypes, SequenceTypes
     # assumes that the obj argument is a string most of the time.
     return isinstance(obj, StringTypes) or not isinstance(obj, SequenceTypes)
 
-def do_flatten(sequence, result, isinstance=isinstance, 
+def do_flatten(sequence, result, isinstance=isinstance,
                StringTypes=StringTypes, SequenceTypes=SequenceTypes):
     for item in sequence:
         if isinstance(item, StringTypes) or not isinstance(item, SequenceTypes):
@@ -349,7 +378,7 @@ def do_flatten(sequence, result, isinstance=isinstance,
         else:
             do_flatten(item, result)
 
-def flatten(obj, isinstance=isinstance, StringTypes=StringTypes, 
+def flatten(obj, isinstance=isinstance, StringTypes=StringTypes,
             SequenceTypes=SequenceTypes, do_flatten=do_flatten):
     """Flatten a sequence to a non-nested list.
 
@@ -367,7 +396,7 @@ def flatten(obj, isinstance=isinstance, StringTypes=StringTypes,
             do_flatten(item, result)
     return result
 
-def flatten_sequence(sequence, isinstance=isinstance, StringTypes=StringTypes, 
+def flatten_sequence(sequence, isinstance=isinstance, StringTypes=StringTypes,
                      SequenceTypes=SequenceTypes, do_flatten=do_flatten):
     """Flatten a sequence to a non-nested list.
 
@@ -388,7 +417,7 @@ def flatten_sequence(sequence, isinstance=isinstance, StringTypes=StringTypes,
 # to_String_for_signature() will use a for_signature() method if the
 # specified object has one.
 #
-def to_String(s, 
+def to_String(s,
               isinstance=isinstance, str=str,
               UserString=UserString, BaseStringTypes=BaseStringTypes):
     if isinstance(s,BaseStringTypes):
@@ -401,11 +430,11 @@ def to_String(s,
     else:
         return str(s)
 
-def to_String_for_subst(s, 
+def to_String_for_subst(s,
                         isinstance=isinstance, str=str, to_String=to_String,
                         BaseStringTypes=BaseStringTypes, SequenceTypes=SequenceTypes,
                         UserString=UserString):
-                        
+
     # Note that the test cases are sorted by order of probability.
     if isinstance(s, BaseStringTypes):
         return s
@@ -421,7 +450,7 @@ def to_String_for_subst(s,
     else:
         return str(s)
 
-def to_String_for_signature(obj, to_String_for_subst=to_String_for_subst, 
+def to_String_for_signature(obj, to_String_for_subst=to_String_for_subst,
                             AttributeError=AttributeError):
     try:
         f = obj.for_signature
@@ -479,7 +508,7 @@ def semi_deepcopy(x):
             return x.__class__(semi_deepcopy_dict(x))
         elif isinstance(x, UserList):
             return x.__class__(_semi_deepcopy_list(x))
-        
+
         return x
 
 
@@ -527,10 +556,10 @@ class Proxy(object):
         """Retrieve the entire wrapped object"""
         return self._subject
 
-    def __cmp__(self, other):
+    def __eq__(self, other):
         if issubclass(other.__class__, self._subject.__class__):
-            return cmp(self._subject, other)
-        return cmp(self.__dict__, other.__dict__)
+            return self._subject == other
+        return self.__dict__ == other.__dict__
 
 class Delegate(object):
     """A Python Descriptor class that delegates attribute fetches
@@ -725,7 +754,7 @@ else:
                     # raised so as to not mask possibly serious disk or
                     # network issues.
                     continue
-                if stat.S_IMODE(st[stat.ST_MODE]) & 0111:
+                if stat.S_IMODE(st[stat.ST_MODE]) & 0o111:
                     try:
                         reject.index(f)
                     except ValueError:
@@ -733,7 +762,7 @@ else:
                     continue
         return None
 
-def PrependPath(oldpath, newpath, sep = os.pathsep, 
+def PrependPath(oldpath, newpath, sep = os.pathsep,
                 delete_existing=1, canonicalize=None):
     """This prepends newpath elements to the given oldpath.  Will only
     add any particular path once (leaving the first one it encounters
@@ -752,7 +781,7 @@ def PrependPath(oldpath, newpath, sep = os.pathsep,
     not move it to the beginning; it will stay where it is in the
     list.
 
-    If canonicalize is not None, it is applied to each element of 
+    If canonicalize is not None, it is applied to each element of
     newpath before use.
     """
 
@@ -774,7 +803,7 @@ def PrependPath(oldpath, newpath, sep = os.pathsep,
         newpaths=list(map(canonicalize, newpaths))
 
     if not delete_existing:
-        # First uniquify the old paths, making sure to 
+        # First uniquify the old paths, making sure to
         # preserve the first instance (in Unix/Linux,
         # the first one wins), and remembering them in normpaths.
         # Then insert the new paths at the head of the list
@@ -815,7 +844,7 @@ def PrependPath(oldpath, newpath, sep = os.pathsep,
     else:
         return sep.join(paths)
 
-def AppendPath(oldpath, newpath, sep = os.pathsep, 
+def AppendPath(oldpath, newpath, sep = os.pathsep,
                delete_existing=1, canonicalize=None):
     """This appends new path elements to the given old path.  Will
     only add any particular path once (leaving the last one it
@@ -833,7 +862,7 @@ def AppendPath(oldpath, newpath, sep = os.pathsep,
     If delete_existing is 0, then adding a path that exists
     will not move it to the end; it will stay where it is in the list.
 
-    If canonicalize is not None, it is applied to each element of 
+    If canonicalize is not None, it is applied to each element of
     newpath before use.
     """
 
@@ -1206,11 +1235,11 @@ def logical_lines(physical_lines, joiner=''.join):
 
 class LogicalLines(object):
     """ Wrapper class for the logical_lines method.
-    
+
         Allows us to read all "logical" lines at once from a
         given file object.
     """
-    
+
     def __init__(self, fileobj):
         self.fileobj = fileobj
 
@@ -1377,8 +1406,9 @@ def make_path_relative(path):
 
 def AddMethod(obj, function, name=None):
     """
-    Adds either a bound method to an instance or an unbound method to
-    a class. If name is ommited the name of the specified function
+    Adds either a bound method to an instance or the function itself
+    (or an unbound method in Python 2) to a class.
+    If name is ommited the name of the specified function
     is used by default.
     Example:
       a = A()
@@ -1391,26 +1421,28 @@ def AddMethod(obj, function, name=None):
       print a.listIndex(5)
     """
     if name is None:
-        name = function.func_name
+        name = function.__name__
     else:
         function = RenameFunction(function, name)
 
     if hasattr(obj, '__class__') and obj.__class__ is not type:
         # "obj" is an instance, so it gets a bound method.
-        setattr(obj, name, MethodType(function, obj, obj.__class__))
+        method = MethodType(function, obj, obj.__class__)
+        setattr(obj, name, method)
     else:
         # "obj" is a class, so it gets an unbound method.
-        setattr(obj, name, MethodType(function, None, obj))
+        function = MethodType(function, None, obj)
+        setattr(obj, name, function)
 
 def RenameFunction(function, name):
     """
     Returns a function identical to the specified function, but with
     the specified name.
     """
-    return FunctionType(function.func_code,
-                        function.func_globals,
+    return FunctionType(function.__code__,
+                        function.__globals__,
                         name,
-                        function.func_defaults)
+                        function.__defaults__)
 
 
 md5 = False
@@ -1432,7 +1464,7 @@ else:
         md5 = True
         def MD5signature(s):
             m = hashlib.md5()
-            m.update(str(s))
+            m.update(to_bytes(str(s)))
             return m.hexdigest()
 
         def MD5filesignature(fname, chunksize=65536):
@@ -1442,10 +1474,10 @@ else:
                 blck = f.read(chunksize)
                 if not blck:
                     break
-                m.update(str(blck))
+                m.update(to_bytes (str(blck)))
             f.close()
             return m.hexdigest()
-            
+
 def MD5collect(signatures):
     """
     Collects a list of signatures into an aggregate signature.
@@ -1494,6 +1526,8 @@ class Null(object):
         return "Null(0x%08X)" % id(self)
     def __nonzero__(self):
         return False
+    def __bool__(self):
+        return False
     def __getattr__(self, name):
         return self
     def __setattr__(self, name, value):
@@ -1516,6 +1550,18 @@ class NullSeq(Null):
 
 del __revision__
 
+def to_bytes (s):
+    if isinstance (s, bytes) or bytes is str:
+        return s
+    else:
+        return bytes (s, 'utf-8')
+
+def to_str (s):
+    if bytes is str:
+        return s
+    else:
+        return str (s, 'utf-8')
+
 # Local Variables:
 # tab-width:4
 # indent-tabs-mode:nil
diff --git a/src/engine/SCons/UtilTests.py b/src/engine/SCons/UtilTests.py
index 9f80e86..9ebb924 100644
--- a/src/engine/SCons/UtilTests.py
+++ b/src/engine/SCons/UtilTests.py
@@ -195,16 +195,16 @@ class UtilTestCase(unittest.TestCase):
             print_tree(node, get_children, showtags=1)
             actual = sys.stdout.getvalue()
             assert withtags == actual, (withtags, actual)
- 
+
             # Test that explicitly setting prune to zero works
             # the same as the default (see above)
             node, expect, withtags = self.tree_case_2(prune=0)
- 
+
             sys.stdout = io.StringIO()
             print_tree(node, get_children, 0)
             actual = sys.stdout.getvalue()
             assert expect == actual, (expect, actual)
- 
+
             sys.stdout = io.StringIO()
             print_tree(node, get_children, 0, showtags=1)
             actual = sys.stdout.getvalue()
@@ -249,7 +249,7 @@ class UtilTestCase(unittest.TestCase):
         assert not is_Dict(())
         assert not is_Dict("")
         if HasUnicode:
-            exec "assert not is_Dict(u'')"
+            exec("assert not is_Dict(u'')")
 
     def test_is_List(self):
         assert is_List([])
@@ -265,12 +265,12 @@ class UtilTestCase(unittest.TestCase):
         assert not is_List({})
         assert not is_List("")
         if HasUnicode:
-            exec "assert not is_List(u'')"
+            exec("assert not is_List(u'')")
 
     def test_is_String(self):
         assert is_String("")
         if HasUnicode:
-            exec "assert is_String(u'')"
+            exec("assert is_String(u'')")
         assert is_String(UserString(''))
         try:
             class mystr(str):
@@ -296,7 +296,7 @@ class UtilTestCase(unittest.TestCase):
         assert not is_Tuple({})
         assert not is_Tuple("")
         if HasUnicode:
-            exec "assert not is_Tuple(u'')"
+            exec("assert not is_Tuple(u'')")
 
     def test_to_String(self):
         """Test the to_String() method."""
@@ -343,10 +343,10 @@ class UtilTestCase(unittest.TestCase):
         os.mkdir(sub2_xxx_exe)
 
         test.write(sub3_xxx_exe, "\n")
-        os.chmod(sub3_xxx_exe, 0777)
+        os.chmod(sub3_xxx_exe, 0o777)
 
         test.write(sub4_xxx_exe, "\n")
-        os.chmod(sub4_xxx_exe, 0777)
+        os.chmod(sub4_xxx_exe, 0o777)
 
         env_path = os.environ['PATH']
 
@@ -732,9 +732,7 @@ bling \
 bling \ bling
 bling
 """
-        # Python 2.7 and beyond require unicode strings.
         fobj = io.StringIO(unicode(content))
-
         lines = LogicalLines(fobj).readlines()
         assert lines == [
             '\n',
@@ -746,8 +744,8 @@ bling
 
     def test_intern(self):
         s1 = silent_intern("spam")
-        # Python 3.x does not have a unicode() global function
-        if sys.version[0] == '2': 
+        # TODO: Python 3.x does not have a unicode() global function
+        if sys.version[0] == '2':
             s2 = silent_intern(unicode("unicode spam"))
         s3 = silent_intern(42)
         s4 = silent_intern("spam")
@@ -760,7 +758,7 @@ class MD5TestCase(unittest.TestCase):
         """Test collecting a list of signatures into a new signature value
         """
         s = list(map(MD5signature, ('111', '222', '333')))
-        
+
         assert '698d51a19d8a121ce581499d7b701668' == MD5collect(s[0:1])
         assert '8980c988edc2c78cc43ccb718c06efd5' == MD5collect(s[0:2])
         assert '53fd88c84ff8a285eb6e0a687e55b8c7' == MD5collect(s)
diff --git a/src/engine/SCons/Variables/PathVariableTests.py b/src/engine/SCons/Variables/PathVariableTests.py
index 4266759..3d9d25c 100644
--- a/src/engine/SCons/Variables/PathVariableTests.py
+++ b/src/engine/SCons/Variables/PathVariableTests.py
@@ -67,7 +67,7 @@ class PathVariableTestCase(unittest.TestCase):
         dne = test.workpath('does_not_exist')
         try:
             o.validator('X', dne, {})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             assert str(e) == 'Path for option X does not exist: %s' % dne, e
         except:
             raise Exception("did not catch expected UserError")
@@ -91,7 +91,7 @@ class PathVariableTestCase(unittest.TestCase):
         f = test.workpath('file')
         try:
             o.validator('X', f, {})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             assert str(e) == 'Directory path for option X is a file: %s' % f, e
         except:
             raise Exception("did not catch expected UserError")
@@ -99,7 +99,7 @@ class PathVariableTestCase(unittest.TestCase):
         dne = test.workpath('does_not_exist')
         try:
             o.validator('X', dne, {})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             assert str(e) == 'Directory path for option X does not exist: %s' % dne, e
         except:
             raise Exception("did not catch expected UserError")
@@ -124,7 +124,7 @@ class PathVariableTestCase(unittest.TestCase):
         f = test.workpath('file')
         try:
             o.validator('X', f, {})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             assert str(e) == 'Path for option X is a file, not a directory: %s' % f, e
         except:
             raise Exception("did not catch expected UserError")
@@ -148,7 +148,7 @@ class PathVariableTestCase(unittest.TestCase):
         d = test.workpath('d')
         try:
             o.validator('X', d, {})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             assert str(e) == 'File path for option X does not exist: %s' % d, e
         except:
             raise Exception("did not catch expected UserError")
@@ -156,7 +156,7 @@ class PathVariableTestCase(unittest.TestCase):
         dne = test.workpath('does_not_exist')
         try:
             o.validator('X', dne, {})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             assert str(e) == 'File path for option X does not exist: %s' % dne, e
         except:
             raise Exception("did not catch expected UserError")
@@ -200,7 +200,7 @@ class PathVariableTestCase(unittest.TestCase):
         dne = test.workpath('does_not_exist')
         try:
             o.validator('X', dne, {})
-        except SCons.Errors.UserError, e:
+        except SCons.Errors.UserError as e:
             expect = 'Path for option X does not exist: %s' % dne
             assert str(e) == expect, e
         else:
@@ -219,7 +219,7 @@ class PathVariableTestCase(unittest.TestCase):
 
         try:
             o.validator('Y', 'value', {})
-        except Exception, e:
+        except Exception as e:
             assert str(e) == 'my_validator() got called for Y, value!', e
         else:
             raise Exception("did not catch expected exception from my_validator()")
diff --git a/src/engine/SCons/Variables/VariablesTests.py b/src/engine/SCons/Variables/VariablesTests.py
index 50f7d13..7f2a978 100644
--- a/src/engine/SCons/Variables/VariablesTests.py
+++ b/src/engine/SCons/Variables/VariablesTests.py
@@ -57,7 +57,7 @@ def check(key, value, env):
 def checkSave(file, expected):
     gdict = {}
     ldict = {}
-    exec open(file, 'rU').read() in gdict, ldict
+    exec(open(file, 'rU').read(), gdict, ldict)
     assert expected == ldict, "%s\n...not equal to...\n%s" % (expected, ldict)
 
 class VariablesTestCase(unittest.TestCase):
diff --git a/src/engine/SCons/Variables/__init__.py b/src/engine/SCons/Variables/__init__.py
index 10f9cb2..b03e5b5 100644
--- a/src/engine/SCons/Variables/__init__.py
+++ b/src/engine/SCons/Variables/__init__.py
@@ -36,11 +36,11 @@ import SCons.Errors
 import SCons.Util
 import SCons.Warnings
 
-from BoolVariable import BoolVariable  # okay
-from EnumVariable import EnumVariable  # okay
-from ListVariable import ListVariable  # naja
-from PackageVariable import PackageVariable # naja
-from PathVariable import PathVariable # okay
+from .BoolVariable import BoolVariable  # okay
+from .EnumVariable import EnumVariable  # okay
+from .ListVariable import ListVariable  # naja
+from .PackageVariable import PackageVariable # naja
+from .PathVariable import PathVariable # okay
 
 
 class Variables(object):
@@ -175,7 +175,7 @@ class Variables(object):
                     sys.path.insert(0, dir)
                 try:
                     values['__name__'] = filename
-                    exec open(filename, 'rU').read() in {}, values
+                    exec(open(filename, 'rU').read(), {}, values)
                 finally:
                     if dir:
                         del sys.path[0]
@@ -211,7 +211,7 @@ class Variables(object):
                         env[option.key] = option.converter(value)
                     except TypeError:
                         env[option.key] = option.converter(value, env)
-                except ValueError, x:
+                except ValueError as x:
                     raise SCons.Errors.UserError('Error converting option: %s\n%s'%(option.key, x))
 
 
@@ -273,7 +273,7 @@ class Variables(object):
             finally:
                 fh.close()
 
-        except IOError, x:
+        except IOError as x:
             raise SCons.Errors.UserError('Error writing options to file: %s\n%s' % (filename, x))
 
     def GenerateHelpText(self, env, sort=None):
diff --git a/src/engine/SCons/compat/__init__.py b/src/engine/SCons/compat/__init__.py
index 5f94df2..0ddbdd5 100644
--- a/src/engine/SCons/compat/__init__.py
+++ b/src/engine/SCons/compat/__init__.py
@@ -82,17 +82,19 @@ def rename_module(new, old):
     except ImportError:
         return False
 
+# TODO: FIXME
 # In 3.x, 'pickle' automatically loads the fast version if available.
 rename_module('pickle', 'cPickle')
 
+# TODO: FIXME
 # In 3.x, 'profile' automatically loads the fast version if available.
 rename_module('profile', 'cProfile')
 
-
+# TODO: FIXME
 # Before Python 3.0, the 'queue' module was named 'Queue'.
 rename_module('queue', 'Queue')
 
-
+# TODO: FIXME
 # Before Python 3.0, the 'winreg' module was named '_winreg'
 rename_module('winreg', '_winreg')
 
diff --git a/src/engine/SCons/cppTests.py b/src/engine/SCons/cppTests.py
index 9f4b875..40236e4 100644
--- a/src/engine/SCons/cppTests.py
+++ b/src/engine/SCons/cppTests.py
@@ -21,6 +21,8 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
+from __future__ import absolute_import
+
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import atexit
diff --git a/src/engine/SCons/dblite.py b/src/engine/SCons/dblite.py
index 707a4f8..b12d320 100644
--- a/src/engine/SCons/dblite.py
+++ b/src/engine/SCons/dblite.py
@@ -1,10 +1,10 @@
 # dblite.py module contributed by Ralf W. Grosse-Kunstleve.
 # Extended for Unicode by Steven Knight.
+from __future__ import print_function
 
 import SCons.compat
 
 import os
-# compat layer imports "cPickle" for us if it's available.
 import pickle
 import shutil
 import time
@@ -13,7 +13,7 @@ keep_all_files = 00000
 ignore_corrupt_dbfiles = 0
 
 def corruption_warning(filename):
-    print "Warning: Discarding corrupt database:", filename
+    print("Warning: Discarding corrupt database:", filename)
 
 try: unicode
 except NameError:
@@ -22,13 +22,16 @@ except NameError:
 else:
     def is_string(s):
         return type(s) in (str, unicode)
-
+def is_bytes(s):
+    return isinstance (s, bytes)
 try:
     unicode('a')
 except NameError:
     def unicode(s): return s
 
 dblite_suffix = '.dblite'
+if bytes is not str:
+    dblite_suffix += '.p3'
 tmp_suffix = '.tmp'
 
 class dblite(object):
@@ -76,7 +79,7 @@ class dblite(object):
         statinfo = os.stat(self._file_name)
         self._chown_to = statinfo.st_uid
         self._chgrp_to = statinfo.st_gid
-      except OSError, e:
+      except OSError as e:
         # db file doesn't exist yet.
         # Check os.environ for SUDO_UID, use if set
         self._chown_to = int(os.environ.get('SUDO_UID', -1))
@@ -89,7 +92,7 @@ class dblite(object):
     else:
       try:
         f = self._open(self._file_name, "rb")
-      except IOError, e:
+      except IOError as e:
         if (self._flag != "c"):
           raise e
         self._open(self._file_name, "wb", self._mode)
@@ -124,7 +127,7 @@ class dblite(object):
     # (e.g. from a previous run as root).  We should still be able to
     # unlink() the file if the directory's writable, though, so ignore
     # any OSError exception  thrown by the chmod() call.
-    try: self._os_chmod(self._file_name, 0777)
+    try: self._os_chmod(self._file_name, 0o777)
     except OSError: pass
     self._os_unlink(self._file_name)
     self._os_rename(self._tmp_name, self._file_name)
@@ -150,10 +153,10 @@ class dblite(object):
     self._check_writable()
     if (not is_string(key)):
       raise TypeError("key `%s' must be a string but is %s" % (key, type(key)))
-    if (not is_string(value)):
-      raise TypeError("value `%s' must be a string but is %s" % (value, type(value)))
+    if (not is_bytes(value)):
+      raise TypeError("value `%s' must be a bytes but is %s" % (value, type(value)))
     self._dict[key] = value
-    self._needs_sync = 0001
+    self._needs_sync = 0o001
 
   def keys(self):
     return list(self._dict.keys())
@@ -173,7 +176,7 @@ class dblite(object):
   def __len__(self):
     return len(self._dict)
 
-def open(file, flag=None, mode=0666):
+def open(file, flag=None, mode=0o666):
   return dblite(file, flag, mode)
 
 def _exercise():
@@ -200,7 +203,7 @@ def _exercise():
   assert db[unicode("ubar")] == unicode("ufoo")
   try:
     db.sync()
-  except IOError, e:
+  except IOError as e:
     assert str(e) == "Read-only database: tmp.dblite"
   else:
     raise RuntimeError("IOError expected.")
@@ -210,13 +213,13 @@ def _exercise():
   db.sync()
   try:
     db[(1,2)] = "tuple"
-  except TypeError, e:
+  except TypeError as e:
     assert str(e) == "key `(1, 2)' must be a string but is <type 'tuple'>", str(e)
   else:
     raise RuntimeError("TypeError exception expected")
   try:
     db["list"] = [1,2]
-  except TypeError, e:
+  except TypeError as e:
     assert str(e) == "value `[1, 2]' must be a string but is <type 'list'>", str(e)
   else:
     raise RuntimeError("TypeError exception expected")
@@ -240,11 +243,10 @@ def _exercise():
   os.unlink("tmp.dblite")
   try:
     db = open("tmp", "w")
-  except IOError, e:
+  except IOError as e:
     assert str(e) == "[Errno 2] No such file or directory: 'tmp.dblite'", str(e)
   else:
     raise RuntimeError("IOError expected.")
-  print "OK"
 
 if (__name__ == "__main__"):
   _exercise()