python-cherrypy fails to build with Python 3.10.0a4.

=================================== FAILURES ===================================
____________________________ ParamsTest.test_syntax ____________________________

self = <cherrypy.test.test_params.ParamsTest testMethod=test_syntax>

    def test_syntax(self):
        if sys.version_info < (3,):
            return self.skip('skipped (Python 3 only)')
        code = textwrap.dedent("""
            class Root:
                @cherrypy.expose
                @cherrypy.tools.params()
                def resource(self, limit: int):
                    return type(limit).__name__
            conf = {'/': {'tools.params.on': True}}
            cherrypy.tree.mount(Root(), config=conf)
            """)
        exec(code)
    
        self.getPage('/resource?limit=0')
>       self.assertStatus(200)

Root       = <class 'cherrypy.test.test_params.Root'>
code       = "\nclass Root:\n    @cherrypy.expose\n    @cherrypy.tools.params()\n    def resource(self, limit: int):\n        return type(limit).__name__\nconf = {'/': {'tools.params.on': True}}\ncherrypy.tree.mount(Root(), config=conf)\n"
conf       = {'/': {'tools.params.on': True}}
self       = <cherrypy.test.test_params.ParamsTest testMethod=test_syntax>

cherrypy/test/test_params.py:60: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/usr/lib/python3.10/site-packages/cheroot/test/webtest.py:327: in assertStatus
    self._handlewebError(msg)
        msg        = 'Status 422 Unprocessable Entity does not match 200'
        self       = <cherrypy.test.test_params.ParamsTest testMethod=test_syntax>
        status     = 200
        tmpl       = 'Status {self.status} does not match {status}'
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <cherrypy.test.test_params.ParamsTest testMethod=test_syntax>
msg = 'Status 422 Unprocessable Entity does not match 200'

    def _handlewebError(self, msg):  # noqa: C901  # FIXME
        print('')
        print('    ERROR: %s' % msg)
    
        if not self.interactive:
>           raise self.failureException(msg)
E           AssertionError: Status 422 Unprocessable Entity does not match 200

msg        = 'Status 422 Unprocessable Entity does not match 200'
self       = <cherrypy.test.test_params.ParamsTest testMethod=test_syntax>

/usr/lib/python3.10/site-packages/cheroot/test/webtest.py:259: AssertionError
----------------------------- Captured stdout call -----------------------------

    ERROR: Status 422 Unprocessable Entity does not match 200

=========================== short test summary info ============================
SKIPPED [1] cherrypy/test/helper.py:321: skipped (not running HTTPS)...
SKIPPED [2] cherrypy/test/test_routes.py:22: Install routes to test RoutesDispatcher code
XPASS cherrypy/test/test_caching.py::CacheTest::test_antistampede #1536
XPASS cherrypy/test/test_conn.py::LimitedRequestQueueTests::test_queue_full #1535
FAILED cherrypy/test/test_params.py::ParamsTest::test_syntax - AssertionError...
= 1 failed, 260 passed, 3 skipped, 1 deselected, 2 xpassed in 80.07s (0:01:20) =
/builddir/build/BUILD/CherryPy-18.6.0/cherrypy/process/wspbus.py:254: RuntimeWarning: The main thread is exiting, but the Bus is in the states.STARTED state; shutting it down automatically now. You must either call bus.block() after start(), or call bus.exit() before the main thread exits.
  warnings.warn(

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.10/fedora-rawhide-x86_64/01922478-python-cherrypy/

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

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.