ipython fails to build with Python 3.9.0b1.

FAIL: IPython.core.tests.test_oinspect.test_render_signature_long
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/builddir/build/BUILDROOT/ipython-7.14.0-2.fc33.x86_64/usr/lib/python3.9/site-packages/IPython/core/tests/test_oinspect.py", line 399, in test_render_signature_long
    nt.assert_in(sig, [
AssertionError: 'long_function(\n    a_really_long_parameter: int,\n    and_another_long_one: bool = False,\n    let_us_make_sure_this_is_looong: Optional[str] = None,\n) -> bool' not found in ['long_function(\n    a_really_long_parameter: int,\n    and_another_long_one: bool = False,\n    let_us_make_sure_this_is_looong: Union[str, NoneType] = None,\n) -> bool', 'long_function(\n    a_really_long_parameter:int,\n    and_another_long_one:bool=False,\n    let_us_make_sure_this_is_looong:Union[str, NoneType]=None,\n) -> bool']
    """Fail immediately, with the given message."""
>>  raise self.failureException("'long_function(\\n    a_really_long_parameter: int,\\n    and_another_long_one: bool = False,\\n    let_us_make_sure_this_is_looong: Optional[str] = None,\\n) -> bool' not found in ['long_function(\\n    a_really_long_parameter: int,\\n    and_another_long_one: bool = False,\\n    let_us_make_sure_this_is_looong: Union[str, NoneType] = None,\\n) -> bool', 'long_function(\\n    a_really_long_parameter:int,\\n    and_another_long_one:bool=False,\\n    let_us_make_sure_this_is_looong:Union[str, NoneType]=None,\\n) -> bool']")
    

This report is automated and not very verbose, sorry about that.

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.9/fedora-rawhide-x86_64/01394887-ipython/

For all our attempts to build ipython with Python 3.9, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.9/package/ipython/

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 3.9:
https://copr.fedorainfracloud.org/coprs/g/python/python3.9/

Let us know here if you have any questions.

Python 3.9 will be included in Fedora 33. To make that update smoother, we're building Fedora packages with early pre-releases of Python 3.9.
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.