Configure with meta/config.

[icemac]

Add support for Python 3.9.

See zopefoundation/meta#94 for the needed changes in meta/config.

[jamadden]

The tests are crashing because coverage can't find a plugin:

Run coverage run -p -m unittest discover -s src
Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.6.13/x64/bin/coverage", line 8, in <module>
    sys.exit(main())
  File "/opt/hostedtoolcache/Python/3.6.13/x64/lib/python3.6/site-packages/coverage/cmdline.py", line 871, in main
    status = CoverageScript().command_line(argv)
  File "/opt/hostedtoolcache/Python/3.6.13/x64/lib/python3.6/site-packages/coverage/cmdline.py", line 588, in command_line
    return self.do_run(options, args)
  File "/opt/hostedtoolcache/Python/3.6.13/x64/lib/python3.6/site-packages/coverage/cmdline.py", line 743, in do_run
    self.coverage.start()
  File "/opt/hostedtoolcache/Python/3.6.13/x64/lib/python3.6/site-packages/coverage/control.py", line 532, in start
    self._init()
  File "/opt/hostedtoolcache/Python/3.6.13/x64/lib/python3.6/site-packages/coverage/control.py", line 275, in _init
    self._plugins = Plugins.load_plugins(self.config.plugins, self.config, self._debug)
  File "/opt/hostedtoolcache/Python/3.6.13/x64/lib/python3.6/site-packages/coverage/plugin_support.py", line 41, in load_plugins
    __import__(module)
ModuleNotFoundError: No module named 'coverage_python_version'

[icemac]

Now CI fails at pushing data to coveralls.io because coverage-python-version is needed there too. (See https://github.com/zopefoundation/zope.interface/pull/243/checks?check_run_id=2515733925)

This step is done via the GitHub action https://github.com/AndreMiras/coveralls-python-action and I do not see a chance there to install coverage-python-version beforehand.

It seems that we either have to remove coverage-python-version or find another way to publish to coveralls.io. @jamadden Do you know why this GitHub action is used instead of installing the Python package and publishing via calling its script?

[mgedmin]

It seems that we either have to remove coverage-python-version or find another way to publish to coveralls.io.

I wonder that nobody else complained about this problem in https://github.com/AndreMiras/coveralls-python-action/issues. Do people rarely use coverage plugins?

For my personal projects I've been uploading to coveralls.io by using the usual pip install coveralls && coveralls in the build script, e.g. https://github.com/mgedmin/check-python-versions/blob/57aa8665d74fee20a56c179608a1c0d79d8b13c0/.github/workflows/build.yml#L60-L65

One issue with that approach is that you need a recent enough version of https://pypi.org/p/coveralls to support GITHUB_TOKEN, and that version no longer supports Python 2.

[jamadden]

One issue with that approach is that you need a recent enough version of https://pypi.org/p/coveralls to support GITHUB_TOKEN, and that version no longer supports Python 2.

That's one of the major reasons I've been using the docker version everywhere.

Do people rarely use coverage plugins?

I think that's right too.

[mgedmin]

I've filed an issue: AndreMiras/coveralls-python-action#17

[icemac]

Let's see if there will be a reaction to AndreMiras/coveralls-python-action#17. Otherwise I'd drop the usage of coverage-python-version as it is not used here in zope.interface.

[mgedmin]

Oh, we're not actually using the coverage-python-version plugin here? Then let's by all means drop it.

[icemac]

Dropped coverage-python-version, let's see if GHA gets green now.

[mgedmin]

The tox.ini setup for -pure environments doesn't work; the rest LGTM.

[mgedmin]

How much coverage are we losing by dropping this from exclude_lines?

[icemac]

I hopefully fixed all the places where this line ignored methods by changing pass to a docstring.

There is still https://coveralls.io/builds/39516428/source?filename=src%2Fzope%2Finterface%2Fcommon%2Fcollections.py#L221 which I do not understand as I thought we have coverage for all Python versions. (There are some other cases which look the same.)

[icemac]

@mgedmin You requested changes to this PR. I think I fixed them. Are you okay with them?

[mgedmin]

lgtm

[icemac]

Thank you for reviewing this PR. 😃