Confirmed.

Repro: Do an ubuntu 20.04 install and choose "experimental zfs" support during install - https://ubuntu.com/blog/zfs-focus-on-ubuntu-20-04-lts-whats-new).  On such a zfs filesystem, the following tests from a ./python -m test.regrtest run fail in 3.10:

11 tests failed:
    test_cmd_line_script test_httpservers test_imp test_import
    test_ntpath test_os test_posixpath test_socket test_unicode_file
    test_unicode_file_functions test_zipimport

Move over to a tmpfs and all but test_httpservers now pass.  test_httpservers tries to create such a path on /tmp

======================================================================
ERROR: test_undecodable_filename (test.test_httpservers.SimpleHTTPServerTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/greg/test/cpython/Lib/test/test_httpservers.py", line 400, in test_undecodable_filename
    with open(os.path.join(self.tempdir, filename), 'wb') as f:
OSError: [Errno 84] Invalid or incomplete multibyte or wide character: '/tmp/tmpnt9ch98x/@test_124227_tmp\udce7w\udcf0.txt'


I expect any filesystem mounted to reject non-UTF8 pathnames to cause similar failures.  Our test suite needs to detect this environment and skip these tests there.