pyproject: fix classifiers

[claui]

PR #337 introduced new classifiers, some of which cause the build to abort:

$ python -m flit build --format wheel
Fetching list of valid trove classifiers                                   I-flit.validate
Unrecognised classifier: 'Programming Language :: Python :: 3 :: 3.10'     E-flit.validate
Unrecognised classifier: 'Programming Language :: Python :: 3 :: 3.7'      E-flit.validate
Unrecognised classifier: 'Programming Language :: Python :: 3 :: 3.8'      E-flit.validate
Unrecognised classifier: 'Programming Language :: Python :: 3 :: 3.9'      E-flit.validate
Config error: Invalid config values (see log)

Looking at PyPI’s list of valid classifiers confirms that minor version classifiers have no intermediate 3 element.

I think the reason that the CI never caught this issue is that because the Makefile seems not to use Flit.

This PR removes the intermediate elements of affected classifiers.

btw:
Shoutout to @woodruffw and others for your amazing work!

[CLAassistant]

All committers have signed the CLA.

[woodruffw]

Thanks for catching this! That’s strange about the Makefile, I’ll look into that… Changes LGTM; I’ll merge this evening. Sent from mobile. Please excuse my brevity.

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[di]

Not sure what happened to the CI pipeline here, opening/closing in an attempt to reset it.

[woodruffw]

Not sure what happened to the CI pipeline here, opening/closing in an attempt to reset it.

Yeah, looks like it was this: https://www.githubstatus.com/incidents/8gpymn7rystj

[woodruffw]

I think the reason that the CI never caught this issue is that because the Makefile seems not to use Flit.

This is strange -- the Makefile should be using Flit via its standard build APIs, since that's what python -m build is invoking under the hood and we have no other build system configured.

I wonder if it's a discrepancy between python -m flit build and python -m build with the Flit backend?

[di]

It also doesn't make sense to me -- would be worthwhile to try to get to the bottom of it.

[woodruffw]

I think it's because flit_core isn't doing that kind of metadata validation.

Locally, python -m flit build fails for me (with the same error @claui saw):

$ python -m flit build
Fetching list of valid trove classifiers  I-flit.validate
Unrecognised classifier: 'Programming Language :: Python :: 3 :: 3.10'  E-flit.validate
Unrecognised classifier: 'Programming Language :: Python :: 3 :: 3.7'  E-flit.validate
Unrecognised classifier: 'Programming Language :: Python :: 3 :: 3.8'  E-flit.validate
Unrecognised classifier: 'Programming Language :: Python :: 3 :: 3.9'  E-flit.validate
Config error: Invalid config values (see log)

But python -m build works, despite definitely using flit_core:

$ python -m build
* Creating venv isolated environment...
* Installing packages in isolated environment... (flit_core >=3.2,<4)
* Getting dependencies for sdist...
* Building sdist...
* Building wheel from sdist
* Creating venv isolated environment...
* Installing packages in isolated environment... (flit_core >=3.2,<4)
* Getting dependencies for wheel...
* Building wheel...
Successfully built pip_audit-2.4.3.tar.gz and pip_audit-2.4.3-py3-none-any.whl

I'll investigate further.

[woodruffw]

Specifically, it looks like the error happens in flit.validate, which is not part of flit_core. Maybe it should be?

[woodruffw]

Ref: pypa/flit#580