Codecoverage assertion error on termination on child process.

[JoanFM]

Describe the bug During the pytest being run an exception from codecoverage is shown which I believe leads to hanging codecov resources.

I think this happens when we are sending a terminate signal from main process to a child process.

Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/multiprocessing/util.py", line 300, in _run_finalizers
    finalizer()
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/multiprocessing/util.py", line 224, in __call__
    res = self._callback(*self._args, **self._kwargs)
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pytest_cov/embed.py", line 99, in cleanup
    _cleanup(_active_cov)
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pytest_cov/embed.py", line 84, in _cleanup
    cov.stop()
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/control.py", line 591, in stop
    self._collector.stop()
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/collector.py", line 353, in stop
    self.pause()
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/collector.py", line 375, in resume
    for tracer in self.tracers:
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/control.py", line 605, in _on_sigterm
    self._atexit("sigterm")
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/control.py", line 599, in _atexit
    self.stop()
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/control.py", line 591, in stop
    self._collector.stop()
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/collector.py", line 350, in stop
    f"Expected current collector to be {self!r}, but it's {self._collectors[-1]!r}"
AssertionError: Expected current collector to be <Collector at 0x7f8854837c10: CTracer>, but it's <Collector at 0x7f8862cf6210: CTracer>
self._collectors:
  <Collector at 0x7f8862cf6210: CTracer>
                      <module> : /opt/hostedtoolcache/Python/3.7.12/x64/bin/pytest:8
                  console_main : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/_pytest/config/__init__.py:185
                          main : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/_pytest/config/__init__.py:143
                _prepareconfig : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/_pytest/config/__init__.py:319
                      __call__ : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pluggy/_hooks.py:265
                     _hookexec : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pluggy/_manager.py:80
                    _multicall : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pluggy/_callers.py:39
          pytest_cmdline_parse : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/_pytest/config/__init__.py:1003
                         parse : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/_pytest/config/__init__.py:1283
                     _preparse : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/_pytest/config/__init__.py:1192
                      __call__ : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pluggy/_hooks.py:265
                     _hookexec : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pluggy/_manager.py:80
                    _multicall : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pluggy/_callers.py:39
 pytest_load_initial_conftests : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pytest_cov/plugin.py:149
                      __init__ : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pytest_cov/plugin.py:200
                         start : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pytest_cov/plugin.py:222
         ensure_topdir_wrapper : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pytest_cov/engine.py:44
                         start : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/pytest_cov/engine.py:222
                         start : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/control.py:567
               _init_for_start : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/control.py:485
                      __init__ : /opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/coverage/collector.py:114

[JoanFM]

May it be related to #1310 ?

[nedbat]

Thanks for the report. Can you give me steps to reproduce the problem? Also, I'm curious how you got the compressed stack trace you show at the end?

[nedbat]

Hi, never mind about the stack trace, that's my own code doing that! :)

Can you try version 6.3.1 and see if it helps? If not, try to avoid using terminate, or, give me a way to try your code myself. Thanks.

[JoanFM]

Hello @nedbat,

I tried but not easy to get a reproducible step.

I will try 6.3.1 wheneve I have the time. Thank you very much for the prompt responses

[nedbat]

Feel free to re-open this if you get more information.