Bug 2345528

python-asgiref fails to build with Python 3.14.05.

____________________ test_async_to_sync_on_callable_object _____________________

    def test_async_to_sync_on_callable_object():
        """
        Tests async_to_sync on a callable class instance
        """
    
        result = {}
    
        class CallableClass:
            async def __call__(self, value):
                await asyncio.sleep(0)
                result["worked"] = True
                return value
    
        # Run it (without warnings)
        with warnings.catch_warnings():
            warnings.simplefilter("error")
            sync_function = async_to_sync(CallableClass())
>           out = sync_function(42)

tests/test_sync.py:456: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
../BUILDROOT/usr/lib/python3.14/site-packages/asgiref/sync.py:236: in __call__
    loop_future.result()
/usr/lib64/python3.14/concurrent/futures/_base.py:441: in result
    return self.__get_result()
/usr/lib64/python3.14/concurrent/futures/_base.py:393: in __get_result
    raise self._exception
/usr/lib64/python3.14/concurrent/futures/thread.py:86: in run
    result = ctx.run(self.task)
/usr/lib64/python3.14/concurrent/futures/thread.py:73: in run
    return fn(*args, **kwargs)
../BUILDROOT/usr/lib/python3.14/site-packages/asgiref/sync.py:260: in _run_event_loop
    asyncio.set_event_loop(loop)
/usr/lib64/python3.14/asyncio/events.py:843: in set_event_loop
    warnings._deprecated('asyncio.set_event_loop', remove=(3,16))
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

name = 'asyncio.set_event_loop'
message = '{name!r} is deprecated and slated for removal in Python {remove}'

    def _deprecated(name, message=_DEPRECATED_MSG, *, remove, _version=sys.version_info):
        """Warn that *name* is deprecated or should be removed.
    
        RuntimeError is raised if *remove* specifies a major/minor tuple older than
        the current Python version or the same version but past the alpha.
    
        The *message* argument is formatted with *name* and *remove* as a Python
        version tuple (e.g. (3, 11)).
    
        """
        remove_formatted = f"{remove[0]}.{remove[1]}"
        if (_version[:2] > remove) or (_version[:2] == remove and _version[3] != "alpha"):
            msg = f"{name!r} was slated for removal after Python {remove_formatted} alpha"
            raise RuntimeError(msg)
        else:
            msg = message.format(name=name, remove=remove_formatted)
>           warn(msg, DeprecationWarning, stacklevel=3)
E           DeprecationWarning: 'asyncio.set_event_loop' is deprecated and slated for removal in Python 3.16

According to https://docs.python.org/dev/whatsnew/3.14.html#id3

asyncio policy system is deprecated and will be removed in Python 3.16. In particular, the following classes and functions are deprecated:
asyncio.AbstractEventLoopPolicy
asyncio.DefaultEventLoopPolicy
asyncio.WindowsSelectorEventLoopPolicy
asyncio.WindowsProactorEventLoopPolicy
asyncio.get_event_loop_policy()
asyncio.set_event_loop_policy()
asyncio.set_event_loop()
Users should use asyncio.run() or asyncio.Runner with loop_factory to use the desired event loop implementation.)


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/fedora-rawhide-x86_64/08650929-python-asgiref/

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

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/

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.