…ython#109810)concurrent.futures: The *executor manager thread* now catchesexceptions when adding an item to the *call queue*. During Pythonfinalization, creating a new thread can now raise RuntimeError. Catchthe exception and call terminate_broken() in this case.Add test_python_finalization_error() to test_concurrent_futures.concurrent.futures._ExecutorManagerThread changes:* terminate_broken() no longer calls shutdown_workers() since the  call queue is no longer working anymore (read and write ends of  the queue pipe are closed).* terminate_broken() now terminates child processes, not only  wait until they complete.* _ExecutorManagerThread.terminate_broken() now holds shutdown_lock  to prevent race conditons with ProcessPoolExecutor.submit().multiprocessing.Queue changes:* Add _terminate_broken() method.* _start_thread() sets _thread to None on exception to prevent  leaking "dangling threads" even if the thread was not started  yet.(cherry picked from commit6351842)