Issue #13812: When a multiprocessing Process child raises an exception, flush stderr after printing the exception traceback.

2 files changed, 4 insertions, 5 deletions

diff --git a/Lib/multiprocessing/forking.py b/Lib/multiprocessing/forking.py
index 47746cb..b7de567 100644
--- a/Lib/multiprocessing/forking.py
+++ b/Lib/multiprocessing/forking.py
@@ -129,8 +129,6 @@ if sys.platform != 'win32':
                     import random
                     random.seed()
                 code = process_obj._bootstrap()
-                sys.stdout.flush()
-                sys.stderr.flush()
                 os._exit(code)
 
             # `w` will be closed when the child exits, at which point `r`
diff --git a/Lib/multiprocessing/process.py b/Lib/multiprocessing/process.py
index 98ce0da..b599f11 100644
--- a/Lib/multiprocessing/process.py
+++ b/Lib/multiprocessing/process.py
@@ -291,16 +291,17 @@ class Process(object):
                 exitcode = e.args[0]
             else:
                 sys.stderr.write(e.args[0] + '\n')
-                sys.stderr.flush()
                 exitcode = 1
         except:
             exitcode = 1
             import traceback
             sys.stderr.write('Process %s:\n' % self.name)
-            sys.stderr.flush()
             traceback.print_exc()
+        finally:
+            util.info('process exiting with exitcode %d' % exitcode)
+            sys.stdout.flush()
+            sys.stderr.flush()
 
-        util.info('process exiting with exitcode %d' % exitcode)
         return exitcode
 
 #