A lot of fixes has been commited to fix this general issue with asyncio at exit.

run_until_complete() doesn't log an error anymore when a BaseException (like KeyboardInterrupted) is raised. The caller is able to decide how to handle it.

The traceback module has been enhanced to try to fix the "AttributeError: 'module' object has no attribute 'open'" error (or at least reduce the risk of such error). A better solution is being developed.

The initial issue was fixed, I close the issue. Thanks for the report Jack. Sorry, I forgot to update this issue since it was splitted in many smaller and more specific issues.