Skip non-string values from sysconfig.get_config_vars()

[domdfcoding]

Summary of changes

sysconfig.get_config_vars() can return values which are not strings (including integers), but the current code assumes all values are strings. This results in an AttributeError. Adding a check for non-string values and skipping them avoids the error.

Closes #3063

Pull Request Checklist

• Changes have tests
• News fragment added in changelog.d/.
  (See documentation for details)

[jaraco]

Normally, I'd ask for a test, but since this is easy_install and deprecated, I'm happy to just push forward with a fix. I'll finish up the draft with a changelog entry and maybe a tweak to the implementation.

[datumbox]

@domdfcoding Thanks for issuing a patch.

@jaraco Are there plans for releasing a hotfix or this is unlikely? The latest version of setuptools brake a couple of jobs downstream on PyTorch and I would like to know if a new version is coming or pin to the previous one. Thanks!

[abravalheri]

@datumbox there was some hick-up with the CI (sometimes PyPy on Windows fails to allocate enough memory), but there should be a release out: https://github.com/pypa/setuptools/releases/tag/v60.7.0.

Please let us know how it goes :)

Thank you very much @domdfcoding for investigating the issue and providing a fix!

[datumbox]

@abravalheri Yes, that worked! Our CI just "saw" the new version and the failure is now resolved. Thanks a lot for the help!