ipython fails to build with Python 3.9.0a6:


======================================================================
FAIL: IPython.core.tests.test_oinspect.test_getdoc
----------------------------------------------------------------------
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-7.14.0-1.fc33.x86_64/usr/lib/python3.9/site-packages/IPython/core/tests/test_oinspect.py", line 256, in test_getdoc
    nt.assert_equal(oinspect.getdoc(a), "standard docstring")
AssertionError: None != 'standard docstring'
    "None != 'standard docstring'" = '%s != %s' % _common_shorten_repr(None, 'standard docstring')
    "None != 'standard docstring'" = self._formatMessage("None != 'standard docstring'", "None != 'standard docstring'")
>>  raise self.failureException("None != 'standard docstring'")
    

======================================================================
FAIL: test_memoryerror (IPython.core.tests.test_ultratb.MemoryErrorTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILDROOT/ipython-7.14.0-1.fc33.x86_64/usr/lib/python3.9/site-packages/IPython/core/tests/test_ultratb.py", line 260, in test_memoryerror
    ip.run_cell(memoryerror_code)
  File "/builddir/build/BUILDROOT/ipython-7.14.0-1.fc33.x86_64/usr/lib/python3.9/site-packages/IPython/testing/tools.py", line 376, in __exit__
    assert s in printed, notprinted_msg.format(s, self.channel, printed)
AssertionError: Did not find 'MemoryError' in printed output (on stdout):
-------
Out[1]: ()

-------

>>  assert 'MemoryError' in 'Out[1]: ()\n', 'Did not find {0!r} in printed output (on {1}):\n-------\n{2!s}\n-------\n'.format('MemoryError', <IPython.testing.tools.AssertPrints object at 0x7fcde25cfa60>.channel, 'Out[1]: ()\n')
    


For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.9/fedora-rawhide-x86_64/01366594-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.