Thought my experience could be helpful.  My env is varies from @brett.cannon in that I'm running Debian 9 (Stretch) on my WSL, which makes me think that these failures have more to do with WSL than any difference in distros? 

Configured with

./configure --with-pydebug

Tests ran with 

./python -m test -j0 -x test_signal -x test_ssl -v

Both test_signal and test_ssl would hang indefinitely.

364 tests OK.

27 tests failed:
    test_asyncio test_asyncore test_concurrent_futures test_epoll
    test_fcntl test_ftplib test_httplib test_httpservers test_import
    test_io test_mmap test_multiprocessing_fork
    test_multiprocessing_forkserver test_multiprocessing_main_handling
    test_multiprocessing_spawn test_os test_posix test_regrtest
    test_selectors test_socket test_source_encoding test_subprocess
    test_sys test_sysconfig test_syslog test_time test_unicode_file

20 tests skipped:
    test_curses test_devpoll test_gdb test_kqueue test_msilib
    test_ossaudiodev test_smtpnet test_socketserver test_startfile
    test_timeout test_tix test_tk test_ttk_guionly test_urllib2net
    test_urllibnet test_winconsoleio test_winreg test_winsound
    test_xmlrpc_net test_zipfile64