Recompiling Plugin on projectLoad fails

[infernalspawn]

when attempting to recompile the plugin during loading of the project i'm getting an error message

[98/220] Compile PyHUD.gen.cpp 1 error generated. In file included from /vol/dev/src/sebastian/UnrealEngine/testProj01/Plugins/UnrealEnginePython/Intermediate/Build/Linux/B4D820EA/UE4Editor/Inc/UnrealEnginePython/PyNativeWidgetHost.gen.cpp:8: In file included from /vol/dev/src/sebastian/UnrealEngine/testProj01/Plugins/UnrealEnginePython/Source/UnrealEnginePython/Public/PyNativeWidgetHost.h:6: In file included from /vol/dev/src/sebastian/UnrealEngine/testProj01/Plugins/UnrealEnginePython/Source/UnrealEnginePython/Public/UnrealEnginePython.h:22: In file included from /usr/include/python2.7/Python.h:8: /usr/include/python2.7/pyconfig.h:3:12: fatal error: 'x86_64-linux-gnu/python2.7/pyconfig.h' file not found # include <x86_64-linux-gnu/python2.7/pyconfig.h>

the directory/file in that the pyconfig.h is pointing to exists

/usr/include/x86_64-linux-gnu/python2.7/pyconfig.h

i'm wondering if there is an include-directory missing somewhere ?
... using:

• current 'master' - branch
• UE4.20
• Ubuntu16.04

thanks for your help!

[rdeioris]

It looks like in 4.20 Epic added its toolchain, so the python plugin is built with a clang++ different from the system one. Unfortunately the ubuntu python releases require a system-specific pyconfig.h header that is in a directory not added to the includes path of the toolchain. Fast (and dirty) solution would be creating x86_64-linux-gnu/python2.7/pyconfig.h in /usr/include/python2.7 to fake the system

[rdeioris]

Another solution would be using an official python releases compiled from sources

[infernalspawn]

i've attempted to symlink /x86_64-linux-gnu/ into /usr/include/python2.7, which seemed to fix that error message, however it is now complaining about re-defined macros, not sure if this is working as expected ;)
/usr/include/python2.7/x86_64-linux-gnu/python2.7/pyconfig.h:1245:9: error: '_XOPEN_SOURCE' macro redefined [-Werror,-Wmacro-redefined]

I'm not sure if i understand correctly with what you mean with 'using an official python releases compiled from sources' ... do you refer to inbuild python in UE 4.20 ? or a prebuild UnrealEnginePython plugin ?

[rdeioris]

I have tried the trick with python 3 (i suppose it will not work on python 2). Eventually add

#undef _XOPEN_SOURCE

before including Python.h in the code

For official python releases i mean the tar.gz you download from official python site and build with ./configure ; make ; make install

[slartibaartfast]

After making a symlink UnrealEnginePython compiled on 4.20, but now I'm getting errors when I try to import packages like asyncio and numpy. Is this related or should I open a new issue?

What do you think is the best way to adapt to the new toolchain? I have ubuntu 18.04 with clang 6.0.0.

For example, here is the error from asyncio that is being loaded from Content/Scripts/AdditionalModules

[2018.09.13-21.39.14:130][499]LogTemp: >>> import asyncio
[2018.09.13-21.39.14:136][499]LogPython: Error: invalid syntax (_base.py, line 414)
[2018.09.13-21.39.14:142][499]LogPython: Error: Traceback (most recent call last):

[2018.09.13-21.39.14:143][499]LogPython: Error: File "", line 1, in

[2018.09.13-21.39.14:143][499]LogPython: Error: File "/usr/lib/python3.6/asyncio/init.py", line 21, in
from .base_events import *

[2018.09.13-21.39.14:143][499]LogPython: Error: File "/usr/lib/python3.6/asyncio/base_events.py", line 17, in
import concurrent.futures

[2018.09.13-21.39.14:143][499]LogPython: Error: File "../../../../../Documents/UnrealProjects/PyMuws/Content/Scripts/AdditionalModules/concurrent/futures/init.py", line 8, in
from concurrent.futures._base import (FIRST_COMPLETED,

[2018.09.13-21.39.14:143][499]LogPython: Error: File "../../../../../Documents/UnrealProjects/PyMuws/Content/Scripts/AdditionalModules/concurrent/futures/_base.py", line 414

[2018.09.13-21.39.14:144][499]LogPython: Error: raise exception_type, self._exception, self._traceback

[2018.09.13-21.39.14:144][499]LogPython: Error: ^

[2018.09.13-21.39.14:144][499]LogPython: Error: SyntaxError: invalid syntax

[rdeioris]

Hi, it looks like you have some kind of nameclash. Your asyncio import is using the modules in the AdditionalModules/concurrent/futures directory instead of the /usr/lib/python3.6/ one

[AdamGlass]

Adding PublicIncludePaths.Add("/usr/include"); makes this work for me and gets me a working plugin. Maybe the toolchain's include path is being configured so as to override the the std paths completely.