Bug 2466678

python-mplcairo fails to build with Python 3.15.0a8.

+ /usr/bin/python3 -c 'import mplcairo.base'
pybind11::handle::dec_ref() is being called while the GIL is either not held or invalid. Please see https://pybind11.readthedocs.io/en/stable/advanced/misc.html#common-sources-of-global-interpreter-lock-errors for debugging advice.
If you are convinced there is no bug in your code, you can #define PYBIND11_NO_ASSERT_GIL_HELD_INCREF_DECREF to disable this check. In that case you have to ensure this #define is consistently used for all translation units linked into a given pybind11 extension, otherwise there will be ODR violations. The failing pybind11::handle::dec_ref() call was triggered on a EnumType object.
terminate called after throwing an instance of 'std::runtime_error'
  what():  pybind11::handle::dec_ref() PyGILState_Check() failure.

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_64/10398276-python-mplcairo/

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

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.