mat2 fails to build with Python 3.15.0a3.

Traceback (most recent call last):
  File "/builddir/build/BUILD/mat2-0.14.0-build/mat2-0.14.0/tests/test_climat2.py", line 27, in test_help
    self.assertIn(b' [-v] [-l]', stdout)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: b' [-v] [-l]' not found in b"usage: mat2 [-h] [-V] [--unknown-members policy] [--inplace] [--no-sandbox]\n            [-L | -s]\n            [-v | -l | --check-dependencies | files ...]\n\nMetadata anonymisation toolkit 2\n\npositional arguments:\n  files                 the files to process\n\noptions:\n  -h, --help            show this help message and exit\n  -V, --verbose         show more verbose status information\n  --unknown-members policy\n                        how to handle unknown members of archive-style files\n                        (policy should be one of: abort, omit, keep) [Default:\n                        abort]\n  --inplace             clean in place, without backup\n  --no-sandbox          Disable bubblewrap's sandboxing\n  -v, --version         show program's version number and exit\n  -l, --list            list all supported fileformats\n  --check-dependencies  check if mat2 has all the dependencies it needs\n  -L, --lightweight     remove SOME metadata\n  -s, --show            list harmful metadata detectable by mat2 without\n                        removing them\n"

======================================================================
FAIL: test_no_arg (tests.test_climat2.TestHelp.test_no_arg)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/mat2-0.14.0-build/mat2-0.14.0/tests/test_climat2.py", line 38, in test_no_arg
    self.assertIn(b' [-v]', stdout)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
AssertionError: b' [-v]' not found in b"usage: mat2 [-h] [-V] [--unknown-members policy] [--inplace] [--no-sandbox]\n            [-L | -s]\n            [-v | -l | --check-dependencies | files ...]\n\nMetadata anonymisation toolkit 2\n\npositional arguments:\n  files                 the files to process\n\noptions:\n  -h, --help            show this help message and exit\n  -V, --verbose         show more verbose status information\n  --unknown-members policy\n                        how to handle unknown members of archive-style files\n                        (policy should be one of: abort, omit, keep) [Default:\n                        abort]\n  --inplace             clean in place, without backup\n  --no-sandbox          Disable bubblewrap's sandboxing\n  -v, --version         show program's version number and exit\n  -l, --list            list all supported fileformats\n  --check-dependencies  check if mat2 has all the dependencies it needs\n  -L, --lightweight     remove SOME metadata\n  -s, --show            list harmful metadata detectable by mat2 without\n                        removing them\n"

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_64/09935245-mat2/

For all our attempts to build mat2 with Python 3.15, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.15/package/mat2/

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.