tox 4: passenv can no longer use factors

[mkoeppe]

My tox.ini files are affected by a change to the parsing of passenv in tox 4:
I can no longer use factors to conditionalize which environment variables are passed:

passenv =
    sagepython, sagewheels:  SAGE_VENV
    sagewheels:              SAGE_SPKG_WHEELS

(from https://github.com/sagemath/sage/blob/develop/pkgs/sagemath-categories/tox.ini#L29)

Originally posted by @mkoeppe in #2699 (comment)

[gaborbernat]

PR to fix it welcome.

[jayaddison]

Hi @mkoeppe - from some local testing, I think that factors are still supported for passenv -- what is no longer supported is multiple factors (or multiple variables) within a single line.

So a refactor like this should work:

passenv =
    sagepython:              SAGE_VENV
    sagewheels:              SAGE_SPKG_WHEELS
    sagewheels:              SAGE_VENV

With tox v4 you can run tox config -k passenv to see what environment variables will be passed through for each environment (and/or filter the results using -e <environment-name>)

(somewhat similar functionality is available in tox v3 by using tox --showconfig)

[mkoeppe]

Thanks a lot for diagnosing and fixing this!

[gaborbernat]

sagepython,sagewheels: SAGE_VENV would have worked also as a temp workaround.

[gaborbernat]

I had to reopen because my fix broke:

commands =
    pytest {posargs: \
      tests --durations 5 --run-integration}

Now our options are to mark this as an expected breaking change or do more complicated filter factor expression matching... than our current regex.