Race condition in test_python_to_cpp_to_python_from_process test on 3.9?

Not sure what's going on, but this test failed again on 3.9, completely unrelated to the actual changes.
I don't know what that test is about, but I thought I'd log it.

Do we have a race condition? Does CPython 3.9 have a race condition?

__________________ test_python_to_cpp_to_python_from_process ___________________

    def test_python_to_cpp_to_python_from_process():
        """Makes sure there is no GIL deadlock when using processes.
    
        This test is for completion, but it was never an issue.
        """
>       assert _run_in_process(_python_to_cpp_to_python) == 0
E       assert -11 == 0
E        +  where -11 = _run_in_process(_python_to_cpp_to_python)

test_gil_scoped.py:81: AssertionError

Start with test_gil_scoped.py at test_python_to_cpp_to_python_from_process and reproduce the failure on Python 3.9. Trace _run_in_process and _python_to_cpp_to_python to determine whether the -11 exit is a race or interpreter-specific failure; done means the cause is established and the test or underlying issue is addressed with regression coverage.