Tests for cygwin are failing because the "tox" command is not found. That's strange and surprising because I'm using the same technique for installing and invoking tox as is used by distutils.

Apparently Python 3.9 is required for tox to get installed in the path. Not sure why.

Apparently Python 3.9 is required for tox to get installed in the path. Not sure why.

The /usr/bin/tox script gets installed by each of python35-tox, python36-tox, python37-tox, python38-tox, and python39-tox in turn, but can only be a part of one of those packages. The maintainer usually chooses the last one, to match the shebang line in the script. I tend to use python -m pytest to avoid needing to know which package the script got installed in, and updating everything when it gets moved (say, when Cygwin adds python 3.10 and makes that the default for command-line scripts).

If you want to find the discussion on the mailing list, I think the script that most recently got mentioned was /usr/bin/sphinx-build moving from python3-sphinx (replaced by python36-sphinx) to python38-sphinx.