import asyncio


async def divide_by(x):
    await asyncio.sleep(.1)
    return 1/x


async def agen():
    try:
        while True:
            yield 1
    finally:

        # Awaiting a failing coroutine is fine
        try:
            await divide_by(0)
        except ZeroDivisionError:
            pass

        # Awaiting a finished task is fine
        try:
            task = asyncio.create_task(divide_by(0))
            await asyncio.sleep(.2)
            await task
        except ZeroDivisionError:
            pass

        # Awaiting an successful unfinished task is fine
        try:
            task = asyncio.create_task(divide_by(1))
            await task
        except ZeroDivisionError:
            pass

        # Awaiting a failing unfinished task triggers the bug
        try:
            task = asyncio.create_task(divide_by(0))
            await task
        except ZeroDivisionError:
            pass

        # The bug can also be reproduced with a future
        try:
            future = asyncio.Future()
            loop = asyncio.get_event_loop()
            loop.call_soon(future.set_exception, ZeroDivisionError())
            await future
        except ZeroDivisionError:
            pass


async def main():
    g = agen()
    async for x in g:
        assert x == 1
        break
    await g.aclose()

if __name__ == '__main__':
    asyncio.run(main())