I was having a hard time figuring out why my program suddenly stopped working without any errors and without keyboard interrupts working. After a lot of digging, I found that there was a simple AttributeError but it wasn't being raised. And it only happened with trio-asyncio running. I managed to come up with this minimal example:

import trio import trio_asyncio async def foo(): async with trio_asyncio.open_loop(): await trio.sleep(0) async def main(): async with trio.open_nursery() as nursery: nursery.start_soon(foo) raise RuntimeError('error!') if __name__ == '__main__': trio.run(main)

Digging further, I found this bit in the _base.py module is to blame:

with trio.CancelScope(shield=True): while not self._stopped.is_set(): await self._main_loop_one()

I'm not familiar with trio_asyncio internals, so I don't know why the shield=True is necessary, but it can clearly cause issues like the one I was experiencing.