bpo-43843: libregrtest uses threading.excepthook

[vstinner]

test.libregrtest now marks a test as ENV_CHANGED (altered the
execution environment) if a thread raises an exception but does not
catch it. It sets a hook on threading.excepthook. Use
--fail-env-changed option to mark the test as failed.

https://bugs.python.org/issue43843

[vstinner]

I expected that many tests will start to fail when run using --fail-env-changed and it would be better for fix them first.

Once CI jobs run on the PR will pass, I will use the buildbot label to test it on buildbots.

[vstinner]

Travis CI:

0:00:13 load avg: 2.42 [ 27/427/1] test_socketserver failed (env changed)
Warning -- Uncaught thread exception

[vstinner]

Azure Pipelines PR: test_logging and test_ssl failed on macOS. The logging issue is https://bugs.python.org/issue43842

2021-04-14T14:42:57.2204700Z 0:03:58 load avg: 6.95 [113/427/1] test_logging failed (env changed) (38.3 sec) -- running: test_nntplib (39.6 sec), test_compileall (35.6 sec)
2021-04-14T14:42:57.2215540Z Exception in thread Thread-25 (serve_forever):
2021-04-14T14:42:57.2231390Z Traceback (most recent call last):
2021-04-14T14:42:57.2333370Z   File "/Users/runner/work/cpython/cpython/Lib/threading.py", line 990, in _bootstrap_inner
2021-04-14T14:42:57.2400340Z     self.run()
2021-04-14T14:42:57.2446870Z   File "/Users/runner/work/cpython/cpython/Lib/threading.py", line 928, in run
2021-04-14T14:42:57.2548480Z     self._target(*self._args, **self._kwargs)
2021-04-14T14:42:57.2617960Z   File "/Users/runner/work/cpython/cpython/Lib/test/test_logging.py", line 863, in serve_forever
2021-04-14T14:42:57.2718400Z     asyncore.loop(poll_interval, map=self._map)
2021-04-14T14:42:57.2818590Z   File "/Users/runner/work/cpython/cpython/Lib/asyncore.py", line 203, in loop
2021-04-14T14:42:57.2920000Z     poll_fun(timeout, map)
2021-04-14T14:42:57.3020900Z   File "/Users/runner/work/cpython/cpython/Lib/asyncore.py", line 144, in poll
2021-04-14T14:42:57.3121080Z     r, w, e = select.select(r, w, e, timeout)
2021-04-14T14:42:57.3222100Z OSError: [Errno 9] Bad file descriptor

The test_ssl failure is unrelated to this PR, I already saw in in other PRs.

=> I created https://bugs.python.org/issue43855 to track it

ERROR: test_msg_callback_deadlock_bpo43577 (test.test_ssl.TestSSLDebug)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/runner/work/cpython/cpython/Lib/test/test_ssl.py", line 4799, in test_msg_callback_deadlock_bpo43577
    s.connect((HOST, server.port))
  File "/Users/runner/work/cpython/cpython/Lib/ssl.py", line 1342, in connect
    self._real_connect(addr, False)
  File "/Users/runner/work/cpython/cpython/Lib/ssl.py", line 1329, in _real_connect
    super().connect(addr)
ConnectionRefusedError: [Errno 61] Connection refused

Azure Pipelines PR: test_asyncio failed on Windows PR win32, this one is unrelated by this PR and is known:

• bpo-43539
• bpo-42124
• bpo-41682

======================================================================
FAIL: test_sendfile_close_peer_in_the_middle_of_receiving (test.test_asyncio.test_sendfile.ProactorEventLoopTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "D:\a\1\s\lib\test\test_asyncio\test_sendfile.py", line 458, in test_sendfile_close_peer_in_the_middle_of_receiving
    self.run_loop(
AssertionError: ConnectionError not raised

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @vstinner for commit 0f26db3 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.

[vstinner]

• buildbot/AMD64 FreeBSD Non-Debug PR: test_logging "OSError: [Errno 9] Bad file descriptor" => https://bugs.python.org/issue43842
• buildbot/AMD64 FreeBSD Shared PR: 1 test_logging "OSError: [Errno 9] Bad file descriptor" => https://bugs.python.org/issue43842
• buildbot/AMD64 Windows10 Pro PR: (grammar := self.grammar()): SyntaxError: invalid syntax
• buildbot/x86-64 macOS PR: test_logging "OSError: [Errno 9] Bad file descriptor" => https://bugs.python.org/issue43842