Hmm.. I'm getting the following failures:

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FAIL: test_4_joining_across_fork_in_worker_thread (test.test_threading.ThreadJoinOnShutdown)
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Traceback (most recent call last):
  File "/home/antoine/cpython/default/Lib/test/test_threading.py", line 726, in test_4_joining_across_fork_in_worker_thread
    self.assertScriptHasOutput(script, "end of main\n")
  File "/home/antoine/cpython/default/Lib/test/test_threading.py", line 651, in assertScriptHasOutput
    rc, out, err = assert_python_ok("-c", script)
  File "/home/antoine/cpython/default/Lib/test/script_helper.py", line 55, in assert_python_ok
    return _assert_python(True, *args, **env_vars)
  File "/home/antoine/cpython/default/Lib/test/script_helper.py", line 46, in _assert_python
    "stderr follows:\n%s" % (rc, err.decode('ascii', 'ignore')))
AssertionError: Process return code is 1, stderr follows:
Traceback (most recent call last):
  File "<string>", line 29, in <module>
AttributeError: 'Thread' object has no attribute '_stopped'

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FAIL: test_5_clear_waiter_locks_to_avoid_crash (test.test_threading.ThreadJoinOnShutdown)
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Traceback (most recent call last):
  File "/home/antoine/cpython/default/Lib/test/test_threading.py", line 784, in test_5_clear_waiter_locks_to_avoid_crash
    self.assertScriptHasOutput(script, output)
  File "/home/antoine/cpython/default/Lib/test/test_threading.py", line 651, in assertScriptHasOutput
    rc, out, err = assert_python_ok("-c", script)
  File "/home/antoine/cpython/default/Lib/test/script_helper.py", line 55, in assert_python_ok
    return _assert_python(True, *args, **env_vars)
  File "/home/antoine/cpython/default/Lib/test/script_helper.py", line 46, in _assert_python
    "stderr follows:\n%s" % (rc, err.decode('ascii', 'ignore')))
AssertionError: Process return code is 1, stderr follows:
Traceback (most recent call last):
  File "<string>", line 29, in <module>
AttributeError: 'Thread' object has no attribute '_stopped'