test_mymanager and test_mymanager_context of test_multiprocessing_spawn.WithManagerTestMyManager failed in this build:

> https://buildbot.python.org/all/#/builders/58/builds/1983/steps/3/logs/stdio

ERROR: test_multiprocessing (test.test_venv.BasicTest)
FAIL: test_async_gen_asyncio_gc_aclose_09 (test.test_asyncgen.AsyncGenAsyncioTest)
FAIL: test_daemon_threads_shutdown_stderr_deadlock (test.test_io.CMiscIOTest)
    self.assertIn("Fatal Python error: could not acquire lock "
AssertionError: "Fatal Python error: could not acquire lock for <_io.BufferedWriter name='<stderr>'> at interpreter shutdown, possibly due to daemon threads" not found in (...)
FAIL: test_daemon_threads_shutdown_stdout_deadlock (test.test_io.CMiscIOTest)
    self.assertIn("Fatal Python error: could not acquire lock "
AssertionError: "Fatal Python error: could not acquire lock for <_io.BufferedWriter name='<stdout>'> at interpreter shutdown, possibly due to daemon threads" not found in ''
Re-running failed tests in verbose mode
Re-running test 'test_venv' in verbose mode
ERROR: test_multiprocessing (test.test_venv.BasicTest)
Re-running test 'test_asyncgen' in verbose mode
Re-running test 'test_multiprocessing_spawn' in verbose mode
FAIL: test_mymanager (test.test_multiprocessing_spawn.WithManagerTestMyManager)
FAIL: test_mymanager_context (test.test_multiprocessing_spawn.WithManagerTestMyManager)
Re-running test 'test_io' in verbose mode
FAIL: test_daemon_threads_shutdown_stderr_deadlock (test.test_io.CMiscIOTest)
    self.assertIn("Fatal Python error: could not acquire lock "
AssertionError: "Fatal Python error: could not acquire lock for <_io.BufferedWriter name='<stderr>'> at interpreter shutdown, possibly due to daemon threads" not found in (...)
FAIL: test_daemon_threads_shutdown_stdout_deadlock (test.test_io.CMiscIOTest)
    self.assertIn("Fatal Python error: could not acquire lock "
AssertionError: "Fatal Python error: could not acquire lock for <_io.BufferedWriter name='<stdout>'> at interpreter shutdown, possibly due to daemon threads" not found in ''