pylint fails to build with Python 3.9.0a2.

=================================== FAILURES ===================================
___________________ test_functional[deprecated_methods_py38] ___________________
test_file = FunctionalTest:deprecated_methods_py38
    @pytest.mark.parametrize("test_file", TESTS, ids=TESTS_NAMES)
    def test_functional(test_file):
        LintTest = (
            LintModuleOutputUpdate(test_file) if UPDATE else LintModuleTest(test_file)
        )
        LintTest.setUp()
>       LintTest._runTest()
tests/test_functional.py:396: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
self = <test_functional.LintModuleTest object at 0x7f547035c6d0>
    def _runTest(self):
        modules_to_check = [self._test_file.source]
        self._linter.check(modules_to_check)
        expected_messages, expected_text = self._get_expected()
        received_messages, received_text = self._get_received()
    
        if expected_messages != received_messages:
            msg = ['Wrong results for file "%s":' % (self._test_file.base)]
            missing, unexpected = multiset_difference(
                expected_messages, received_messages
            )
            if missing:
                msg.append("\nExpected in testdata:")
                msg.extend(" %3d: %s" % msg for msg in sorted(missing))
            if unexpected:
                msg.append("\nUnexpected in testdata:")
                msg.extend(" %3d: %s" % msg for msg in sorted(unexpected))
>           pytest.fail("\n".join(msg))
E           Failed: Wrong results for file "deprecated_methods_py38":
E           
E           Expected in testdata:
E             15: deprecated-method
E             16: deprecated-method
tests/test_functional.py:336: Failed
_____________________ test_functional[member_checks_py37] ______________________
test_file = FunctionalTest:member_checks_py37
    @pytest.mark.parametrize("test_file", TESTS, ids=TESTS_NAMES)
    def test_functional(test_file):
        LintTest = (
            LintModuleOutputUpdate(test_file) if UPDATE else LintModuleTest(test_file)
        )
        LintTest.setUp()
>       LintTest._runTest()
tests/test_functional.py:396: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
self = <test_functional.LintModuleTest object at 0x7f54696dc550>
    def _runTest(self):
        modules_to_check = [self._test_file.source]
        self._linter.check(modules_to_check)
        expected_messages, expected_text = self._get_expected()
        received_messages, received_text = self._get_received()
    
        if expected_messages != received_messages:
            msg = ['Wrong results for file "%s":' % (self._test_file.base)]
            missing, unexpected = multiset_difference(
                expected_messages, received_messages
            )
            if missing:
                msg.append("\nExpected in testdata:")
                msg.extend(" %3d: %s" % msg for msg in sorted(missing))
            if unexpected:
                msg.append("\nUnexpected in testdata:")
                msg.extend(" %3d: %s" % msg for msg in sorted(unexpected))
>           pytest.fail("\n".join(msg))
E           Failed: Wrong results for file "member_checks_py37":
E           
E           Unexpected in testdata:
E              5: no-member
tests/test_functional.py:336: Failed


For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.9/fedora-rawhide-x86_64/01160829-pylint/

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

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.