pychromecast fails to build with Python 3.14.0b1.

The error comes from protobuf which doesn't work with Python 3.14 - it's reported in https://bugzilla.redhat.com/show_bug.cgi?id=2343969 but as we approach mass rebuild, I decided to raise this also with some of the dependent packages to increase visibility of the issue.

+ /usr/bin/python3 -sP /usr/lib/rpm/redhat/import_all_modules.py pychromecast
Check import: pychromecast
Traceback (most recent call last):
  File "/usr/lib/rpm/redhat/import_all_modules.py", line 171, in <module>
    main()
    ~~~~^^
  File "/usr/lib/rpm/redhat/import_all_modules.py", line 167, in main
    import_modules(modules)
    ~~~~~~~~~~~~~~^^^^^^^^^
  File "/usr/lib/rpm/redhat/import_all_modules.py", line 100, in import_modules
    importlib.import_module(module)
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
  File "/usr/lib64/python3.14/importlib/__init__.py", line 88, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1398, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1371, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1342, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 938, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 762, in exec_module
  File "<frozen importlib._bootstrap>", line 491, in _call_with_frames_removed
  File "/builddir/build/BUILD/pychromecast-13.1.0-build/BUILDROOT/usr/lib/python3.14/site-packages/pychromecast/__init__.py", line 14, in <module>
    from . import socket_client
  File "/builddir/build/BUILD/pychromecast-13.1.0-build/BUILDROOT/usr/lib/python3.14/site-packages/pychromecast/socket_client.py", line 23, in <module>
    from . import cast_channel_pb2
  File "/builddir/build/BUILD/pychromecast-13.1.0-build/BUILDROOT/usr/lib/python3.14/site-packages/pychromecast/cast_channel_pb2.py", line 6, in <module>
    from google.protobuf import descriptor as _descriptor
  File "/usr/lib64/python3.14/site-packages/google/protobuf/descriptor.py", line 47, in <module>
    from google.protobuf.pyext import _message
TypeError: Metaclasses with custom tp_new are not supported.

https://docs.python.org/3.14/whatsnew/3.14.html

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.14-b1/fedora-rawhide-x86_64/09026704-pychromecast/

For all our attempts to build pychromecast with Python 3.14, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.14-b1/package/pychromecast/

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 3.14:
https://copr.fedorainfracloud.org/coprs/g/python/python3.14-b1/

Let us know here if you have any questions.

Python 3.14 is planned to be included in Fedora 43.
To make that update smoother, we're building Fedora packages with all pre-releases of Python 3.14.
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.