Test handling of an exception when the nursery has no active host task

triotest.py

import trio


async def error_after(delay):
    await trio.sleep(delay)
    raise Exception('foo')


async def somegenerator():
    try:
        async with trio.open_nursery() as nursery:
            nursery.start_soon(error_after, 1)
            yield
    except BaseException as exc:
        print(exc)

async def main():
    async for _ in gen:
        await trio.sleep(2)

gen = somegenerator()
trio.run(main)