MSVC 2011 - 2012 bug: Blender Startup Failure when called from a process without SDOUT (Python crashes) #40907

New Issue

Ignacio · 2014-07-01T17:42:26+02:00

Ignacio commented

2014-07-01 17:42:26 +02:00

Blender Version
Broken: Blender on Windows built with MSVC 11.0 or later (includes 2.71 release)
Worked: 2.70a and earlier

When Blender is called from a subprocess with no STDOUT available, the Py_Initialize procedure will cause a fatal error, due to a bug in more recent MSVC versions. (This issue will be fixed in MSVC 14)

The respective Issue on the Python Tracker:
http://bugs.python.org/issue17797

This breaks the Auto-Import functionality for blend files in Unity (unity3d.com), where a .blend dropped in an asset directory will be automatically converted to FBX by calling the Blender executable (and the FBX exporter python module).

I can confirm that a possible workaround outlined at http://bugs.python.org/issue17797#msg201964 fixes the issue. This would imply modifying pythonrun.c and replacing the Python34.dll with a modified version.

**Blender Version** Broken: Blender on Windows built with MSVC 11.0 or later (includes 2.71 release) Worked: 2.70a and earlier When Blender is called from a subprocess with no STDOUT available, the Py_Initialize procedure will cause a fatal error, due to a bug in more recent MSVC versions. (This issue will be fixed in MSVC 14) The respective Issue on the Python Tracker: http://bugs.python.org/issue17797 This breaks the Auto-Import functionality for blend files in Unity (unity3d.com), where a .blend dropped in an asset directory will be automatically converted to FBX by calling the Blender executable (and the FBX exporter python module). I can confirm that a possible workaround outlined at http://bugs.python.org/issue17797#msg201964 fixes the issue. This would imply modifying pythonrun.c and replacing the Python34.dll with a modified version.

Ignacio commented

2014-07-01 17:42:26 +02:00

Changed status to: 'Open'

Ignacio commented

2014-07-01 17:42:26 +02:00

Added subscriber: @Ignaramus

blender-admin commented

2014-07-01 17:42:26 +02:00

blender/blender#41053 was marked as duplicate of this issue

blender-admin commented

2014-07-01 17:42:26 +02:00

blender/blender#41129 was marked as duplicate of this issue

blender-admin commented

2014-07-01 17:42:26 +02:00

blender/blender#40928 was marked as duplicate of this issue

blender-admin commented

2014-07-01 17:42:26 +02:00

blender/blender#41089 was marked as duplicate of this issue

blender-admin commented

2014-07-01 17:42:26 +02:00

blender/blender#41101 was marked as duplicate of this issue

Ignacio commented

2014-07-01 18:12:44 +02:00

Modified pythonrun.c with fixes according to http://bugs.python.org/issue17797#msg201964

Ignacio commented

2014-07-01 18:13:37 +02:00

Fixed DLL for 32-Bit Windows

Ignacio commented

2014-07-01 18:14:45 +02:00

Fixed DLL for 64-Bit Windows

Bastien Montagne commented

2014-07-01 19:30:49 +02:00

Added subscribers: @ideasman42, @MartijnBerger, @mont29

Bastien Montagne commented

2014-07-01 19:30:49 +02:00

Thanks for tracking that issue down!

Adding our py & win maintainers here too.

I doubt we’ll ever agree to distribute a patched version of python with our Blender but at least users that really need that feature from Unity now have a workaround… I’d bet this report will stay open for quite a bit of time (thanks M$).

PS: There may be another way around that issue, though, less intrusive - python can call processes with its own stdin/out/err, so a simple modification of Unity script to feature such fake streams might solve it, without having to replace whole py dll?

Thanks for tracking that issue down! Adding our py & win maintainers here too. I doubt we’ll ever agree to distribute a patched version of python with our Blender but at least users that really need that feature from Unity now have a workaround… I’d bet this report will stay open for quite a bit of time (thanks M$). PS: There may be another way around that issue, though, less intrusive - python can call processes with its own stdin/out/err, so a simple modification of Unity script to feature such fake streams might solve it, without having to replace whole py dll?

Ignacio commented

2014-07-01 19:41:37 +02:00

The Blender process itself crashes on Python Initialization, so there is no hope to have the script run in the first place, Unity itself does not use Python. They should be able to work around this, depending on how they handle subprocesses, but not a simply as that.

Bastien Montagne commented

2014-07-01 21:43:14 +02:00

Ah ok… well, yes, not so simple in this case, indeed :/

Vitor Balbio commented

2014-07-02 02:51:43 +02:00

Added subscriber: @vitorbalbio-3

Bastien Montagne changed title from ~~Blender Startup Failure on Windows when called from a process without SDOUT (Broken Unity Blender Auto-Import)~~ to MSVC 2011 - 2012 bug: Blender Startup Failure when called from a process without SDOUT (Python crashes)

2014-07-02 16:05:56 +02:00

Bastien Montagne commented

2014-07-02 16:06:55 +02:00

Set prio to 'Low', because we can’t do anything really here. I think it’s worth keeping it open though, so other users hitting the issue can find it (and the workaround)…