Bug 2447915

Summary: python-attrs fails to build with Python 3.15: TestMatchesRe.test_catches_invalid_func: 'func' must be one of None, fullmatch, prefixmatch, search.
Product: [Fedora] Fedora Reporter: Karolina Surma <ksurma>
Component: python-attrsAssignee: Lumír Balhar <lbalhar>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
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Version: rawhideCC: ksurma, lbalhar, mhroncok, python-packagers-sig, vstinner
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Description Karolina Surma 2026-03-16 10:43:14 UTC
python-attrs fails to build with Python 3.15.0a7.

___________________ TestMatchesRe.test_catches_invalid_func ____________________

self = <tests.test_validators.TestMatchesRe object at 0x7f659d55b570>

    def test_catches_invalid_func(self):
        """
        Invalid match functions are caught.
        """
        with pytest.raises(ValueError) as ei:
            matches_re("a", 0, lambda: None)
    
>       assert (
            "'func' must be one of None, fullmatch, match, search."
            == ei.value.args[0]
        )
E       assert "'func' must ...atch, search." == "'func' must ...atch, search."
E         
E         - 'func' must be one of None, fullmatch, prefixmatch, search.
E         ?                                        ------
E         + 'func' must be one of None, fullmatch, match, search.

tests/test_validators.py:230: AssertionError

https://docs.python.org/3.15/whatsnew/3.15.html

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.15/fedora-rawhide-x86_64/10222370-python-attrs/

For all our attempts to build python-attrs with Python 3.15, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.15/package/python-attrs/

Testing and mass rebuild of packages is happening in copr.
You can follow these instructions to test locally in mock if your package builds with Python 3.15:
https://copr.fedorainfracloud.org/coprs/g/python/python3.15/

Let us know here if you have any questions.

Python 3.15 is planned to be included in Fedora 45.
To make that update smoother, we're building Fedora packages with all pre-releases of Python 3.15.
A build failure prevents us from testing all dependent packages (transitive [Build]Requires),
so if this package is required a lot, it's important for us to get it fixed soon.

We'd appreciate help from the people who know this package best,
but if you don't want to work on this now, let us know so we can try to work around it on our side.

Comment 1 Victor Stinner 2026-03-18 13:54:50 UTC
I proposed a fix upstream: https://github.com/python-attrs/attrs/pull/1530.