Continuous integration build failure: tox dependency installation

[jayaddison]

Recent continuous integration builds have been failing with an error similar to the following on Ubuntu and Windows platforms:

  File "/opt/hostedtoolcache/Python/3.11.0/x64/lib/python3.11/site-packages/tox/config/loader/str_convert.py", line 66, in to_command
    if args[0] != "-" and args[0].startswith("-"):
       ~~~~^^^

This seems to be related to installation of dependencies by tox, based on this log output line:

    self.installer.install(requirements_file, PythonRun.__name__, "deps")

(which corresponds to this line of the tox.ini configuration, I think)

[jayaddison]

On closer inspection, I think that something has changed in a recent version of tox, related to handling of environment names.

We use an environment name, py-darwin, to install a precompiled binary wheel of lxml on OSX-based platforms.

That may also explain why this failure occurs on Ubuntu and Windows, and the failure does not occur on OSX.

[jayaddison]

On closer inspection, I think that something has changed in a recent version of tox, related to handling of environment names.

Reported upstream to tox at tox-dev/tox#2695.