There is a race with the KeyboardInterrupt exception in the asyncio.base_events.BaseEventLoop.run_forever() method. While an attempt is made to restore the environment to its previous state before run_forever() completes with a try...finally, a couple items find themselves outside the try...finally. Specifically, a badly timed KeyboardInterrupt will mean that, neither the self._thread_id value or the hooks set by sys.set_asyncgen_hooks() will be correctly restored. Both of these should be moved inside the try...finally.

This applies to all existing version of Python on all platforms.