问Asyncio.run给出的RuntimeError循环是封闭的

EN

import aiocoap
import aiocoap.resource as resource


class CoAPServer(resource.Resource):
    def __init__(self) -> None:
        super().__init__()

    async def render_get(self, request):
        print("Received GET request ...")
        return aiocoap.Message(code=aiocoap.GET, payload="hello friend".encode('utf8'))

    async def render_post(self, request):
        print("Received POST request ...")
        return aiocoap.Message(code=aiocoap.CHANGED, payload="that's me".encode('utf8'))

async def main():
    root = resource.Site()
    root.add_resource(['demo'], CoAPServer)
    task = asyncio.create_task(aiocoap.Context.create_server_context(root, bind=('127.0.0.1', 5683)))
    await task

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

Exception ignored in: <function RecvmsgSelectorDatagramTransport.__del__ at 0x7f9a04c57310>
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/dist-packages/aiocoap/util/asyncio/recvmsg.py", line 95, in __del__
    self.close()
  File "/usr/local/lib/python3.8/dist-packages/aiocoap/util/asyncio/recvmsg.py", line 83, in close
    self._loop.call_soon(self._protocol.connection_lost, None)
  File "/usr/lib/python3.8/asyncio/base_events.py", line 719, in call_soon
    self._check_closed()
  File "/usr/lib/python3.8/asyncio/base_events.py", line 508, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed

if __name__ == "__main__":
    asyncio.get_event_loop().run_forever()