$ ./python -We -m test test_coroutines
Run tests sequentially
0:00:00 load avg: 0.29 [1/1] test_coroutines
Exception ignored in: <coroutine object OriginTrackingTest.test_origin_tracking_warning.<locals>.corofn at 0x7fc5fc692cb8>
Traceback (most recent call last):
  File "/home/serhiy/py/cpython/Lib/warnings.py", line 511, in _warn_unawaited_coroutine
    warn(msg, category=RuntimeWarning, stacklevel=2, source=coro)
RuntimeWarning: coroutine 'OriginTrackingTest.test_origin_tracking_warning.<locals>.corofn' was never awaited
test test_coroutines failed -- Traceback (most recent call last):
  File "/home/serhiy/py/cpython/Lib/test/test_coroutines.py", line 2167, in test_origin_tracking_warning
    msg = check(0, f"coroutine '{corofn.__qualname__}' was never awaited")
  File "/home/serhiy/py/cpython/Lib/test/test_coroutines.py", line 2161, in check
    self.assertTrue(len(wlist) == 1)
AssertionError: False is not true

test_coroutines failed

1 test failed:
    test_coroutines

Total duration: 371 ms
Tests result: FAILURE

This isn't release blocker, because the test is failed, not crashed, and seems this is just a test issue.

Nathaniel, this seems to be related to coro-origin-tracking.

Ok, yeah, that's a test that a warning is emitted, which fails when the warning is converted into an error instead. Need to normalize the warnings filter settings inside that test, I guess.

How does this not cause the same problem for every other test that uses assertWarns though?

I think assertWarns just handles it. Maybe the test should be converted to use it?

Or to use assertWarnsRegex

New changeset 2efb9735899c7c642f3e75a121af82b1679577d3 by Nathaniel J. Smith in branch 'master':
bpo-32733: Make test_coroutines robust against -Werror (GH-5487)
https://github.com/python/cpython/commit/2efb9735899c7c642f3e75a121af82b1679577d3

New changeset 709f6ad7f84855ebdbe3e7702571b0e1447b885b by Nathaniel J. Smith (Miss Islington (bot)) in branch '3.7':
bpo-32733: Make test_coroutines robust against -Werror (GH-5487) (GH-5490)
https://github.com/python/cpython/commit/709f6ad7f84855ebdbe3e7702571b0e1447b885b

Thank you Nathaniel. And congratulate with getting core developer status!

Thanks!