New submission from Pierre Glaser <pierregla...@msn.com>:
If I am not mistaken, when creating a new process on Python3.7 and later on Windows, if using a virtualenv, Python now uses a launcher. The launcher is being notified that it must create a virtual-environment Python (and not a system Python) program using the __PYVENV_LAUNCHER__ environment variable, passed as part of the environment of launcher process created using in _winapi.CreateProcess (see https://github.com/python/cpython/blob/9008be303a89bfab8c3314c6a42330b5523adc8b/Lib/multiprocessing/popen_spawn_win32.py#L73-L75) However, if I am not mistaken `env` is not passed at the right position (https://github.com/python/cpython/blob/9008be303a89bfab8c3314c6a42330b5523adc8b/Modules/_winapi.c#L1062-L1068). These lines were part of a bugfix patch (see https://bugs.python.org/issue35797), solving an issue for multiprocessing-based packages. We ended trying to backport to loky (https://github.com/tomMoral/loky, a multiprocessing-based package) but the bug was not fixed. Passing 'env' correctly fixed the bug. Two things: - It is hard to provide a reproducer for this issue as it requires patching the CPython source code. - I don't understand why env being not passed correctly does not manifest itself in the test-suite. What is even more troubling is that even with this bug, the virtualenv launcher seems to get that a virtualenv is used when creating processes in multiprocessing (at least, sys.path includes the path/to/venv/lib/python3.x/site-packages). However, I am not familiar with the virtualenv launcher for python3.7+ and windows. ---------- components: Windows messages: 351650 nosy: paul.moore, pierreglaser, pitrou, steve.dower, tim.golden, zach.ware priority: normal severity: normal status: open title: environment variables not passed correctly using new virtualenv launching in windows and python3.7+ type: crash versions: Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue38092> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
