PYTHONPATH not honored (not even for sub-interpreters)

[eudoxos]

I am trying to run python interpreter with modified sys.path. This is normally done by setting the PYTHONPATH environment variable. I understand wenv cannot do this due to path translation when called from Linux shell:

$ PYTHONPATH=foo:bar python -c'import sys; print(sys.path)'
['', '/home/eudoxos/foo', '/home/eudoxos/bar', '/usr/lib/python310.zip', '/usr/lib/python3.10', # .... 
$ PYTHONPATH='foo;bar' wenv python -c'import sys; print(sys.path)'
['C:\\python-3.8.5.stable\\Lib', 'C:\\python-3.8.5.stable', 'C:\\python-3.8.5.stable\\lib\\site-packages']
# where is foo and bar?

But now I have a script running under wenv, which runs a child python process, wanthing to pass it some paths through its environment PYTHONPATH. This work both under Linux and under Windows, but not under wenv. The one-liner is like this (explanation: the main python calls another python as subprocess, passing it PYTHONPATH through an argument to subprocess.call):

$ wenv python -c "import sys, subprocess; subprocess.call([sys.executable,'-c','import sys; print(sys.path)'],env={'PYTHONPATH':'foo;bar'})"
['C:\\python-3.8.5.stable\\Lib', 'C:\\python-3.8.5.stable', 'C:\\python-3.8.5.stable\\lib\\site-packages']
# where is foo and bar?

As I checked, sys.executable is correct in the main interpreter:

$ wenv python -c'import sys; print(sys.executable)'
C:\python-3.8.5.stable\python.exe

Any ideas?

[s-m-e]

That's an interesting one ... I extended your second to last test a bit and switched to Popen. Still the same. But ...

wenv python -c "import sys, subprocess; p=subprocess.Popen([sys.executable,'-c','import sys, os; print(sys.path); print(os.environ)'],env={'PYTHONPATH':'foo;bar', 'BARFOO': 'FOOBAR'}); p.wait()"

... the two variables are clearly passed on: environ({'PYTHONPATH': 'foo;bar', 'BARFOO': 'FOOBAR', [...].

This behavior has its origin in the fact that wenv uses an embedded Python interpreter, which tends to have some odd edge cases in path handling. I am working around this using a pth-file. If you remove this file, your code works as expected.

I forgot the full backstory of the pth-file - i.e. why I needed it in the first place - and I did not put it into the comments. My mistake. I'll to trace the commit(s) back. It was once part of another package, zugbruecke, and I believe that some tests were not working without this hack.

[s-m-e]

This was an issue with coverage (not) running under wenv python, see here. This was a long time ago - maybe I can get rid of it now.

[eudoxos]

For our use-case, it would be sufficient to override PYTHONPATH via wenv.json. Is that possible?

[s-m-e]

@eudoxos I need to look into if (how) this is possible. In the meantime, have you tried deleting the pth file? It's located in your virtual environment under share/wenv/winX/drive_c/python-3.Y.Z.stable/python3Y._pth. It gets created during wenv init so you can delete it in your CI pipeline in a subsequently triggered command. X is either 32 or 64. Y and Z are the Wine Python's minor and micro versions.