Issue #8876: distutils now falls back to copying files when hard linking doesn't work.

This allows use with special filesystems such as VirtualBox shared folders.

1 files changed, 21 insertions, 13 deletions

diff --git a/Lib/distutils/file_util.py b/Lib/distutils/file_util.py
index 7b14efb..b3fee35 100644
--- a/Lib/distutils/file_util.py
+++ b/Lib/distutils/file_util.py
@@ -80,7 +80,8 @@ def copy_file(src, dst, preserve_mode=1, preserve_times=1, update=0,
     (os.symlink) instead of copying: set it to "hard" or "sym"; if it is
     None (the default), files are copied.  Don't set 'link' on systems that
     don't support it: 'copy_file()' doesn't check if hard or symbolic
-    linking is available.
+    linking is available. If hardlink fails, falls back to
+    _copy_file_contents().
 
     Under Mac OS, uses the native file copy function in macostools; on
     other systems, uses '_copy_file_contents()' to copy file contents.
@@ -132,24 +133,31 @@ def copy_file(src, dst, preserve_mode=1, preserve_times=1, update=0,
     # (Unix only, of course, but that's the caller's responsibility)
     elif link == 'hard':
         if not (os.path.exists(dst) and os.path.samefile(src, dst)):
-            os.link(src, dst)
+            try:
+                os.link(src, dst)
+                return (dst, 1)
+            except OSError:
+                # If hard linking fails, fall back on copying file
+                # (some special filesystems don't support hard linking
+                #  even under Unix, see issue #8876).
+                pass
     elif link == 'sym':
         if not (os.path.exists(dst) and os.path.samefile(src, dst)):
             os.symlink(src, dst)
+            return (dst, 1)
 
     # Otherwise (non-Mac, not linking), copy the file contents and
     # (optionally) copy the times and mode.
-    else:
-        _copy_file_contents(src, dst)
-        if preserve_mode or preserve_times:
-            st = os.stat(src)
-
-            # According to David Ascher <da@ski.org>, utime() should be done
-            # before chmod() (at least under NT).
-            if preserve_times:
-                os.utime(dst, (st[ST_ATIME], st[ST_MTIME]))
-            if preserve_mode:
-                os.chmod(dst, S_IMODE(st[ST_MODE]))
+    _copy_file_contents(src, dst)
+    if preserve_mode or preserve_times:
+        st = os.stat(src)
+
+        # According to David Ascher <da@ski.org>, utime() should be done
+        # before chmod() (at least under NT).
+        if preserve_times:
+            os.utime(dst, (st[ST_ATIME], st[ST_MTIME]))
+        if preserve_mode:
+            os.chmod(dst, S_IMODE(st[ST_MODE]))
 
     return (dst, 1)