python-m2r fails to build with Python 3.10.0a4.

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FAIL: test_no_file (tests.test_cli.TestConvert)
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Traceback (most recent call last):
  File "/builddir/build/BUILD/m2r-66f4a5a500cdd9fc59085106bff082c9cadafaf3/tests/test_cli.py", line 61, in test_no_file
    self.assertIn('optional arguments:', message)
AssertionError: 'optional arguments:' not found in 'usage: m2r.py [-h] [--overwrite] [--dry-run] [--no-underscore-emphasis]\n              [--parse-relative-links] [--anonymous-references]\n              [--disable-inline-math]\n              [input_file ...]\n\npositional arguments:\n  input_file            files to convert to reST format\n\noptions:\n  -h, --help            show this help message and exit\n  --overwrite           overwrite output file without confirmaion\n  --dry-run             print conversion result and not save output file\n  --no-underscore-emphasis\n                        do not use underscore (_) for emphasis\n  --parse-relative-links\n                        parse relative links into ref or doc directives\n  --anonymous-references\n                        use anonymous references in generated rst\n  --disable-inline-math\n                        disable parsing inline math\n'

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Ran 85 tests in 0.632s

FAILED (failures=1, skipped=1)
Test failed: <unittest.runner.TextTestResult run=85 errors=0 failures=1>

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.10/fedora-rawhide-x86_64/01865162-python-m2r/

For all our attempts to build python-m2r with Python 3.10, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.10/package/python-m2r/

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 3.10:
https://copr.fedorainfracloud.org/coprs/g/python/python3.10/

Let us know here if you have any questions.

Python 3.10 will be included in Fedora 35. To make that update smoother, we're building Fedora packages with early pre-releases of Python 3.10.
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.