Simple script that sends a message raises RuntimeError: Event loop is closed on Windows

[evgfilim1]

Context

• Operating System: Windows 10
• Python Version: 3.9, 3.10
• aiogram version: 2.19, 3.0.0b2
• aiohttp version: 3.8.1

Expected Behavior

Process finishes gracefully

Current Behavior

Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x00000207916D4040>
Traceback (most recent call last):
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 746, in call_soon
    self._check_closed()
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\asyncio\base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed

Failure Information (for bugs)

Steps to Reproduce

import asyncio

from aiogram import Bot

TOKEN = ""  # put your token here
CHAT_ID = 0  # put your user ID here


async def main():
    bot = Bot(TOKEN)
    await bot.send_message(CHAT_ID, "Hello there!")
    await bot.session.close()  # replace with `await bot.close()` on 2.x
    # await asyncio.sleep(0.1)


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

If you uncomment sleep method, it works fine and finishes without traceback. I guess the problem is in aiohttp.
The message is delivered anyway, with or without sleep

[evgfilim1]

Related:

aio-libs/aiohttp#6635 (same problem)
https://docs.aiohttp.org/en/stable/client_advanced.html#graceful-shutdown (workaround is described in docs)
aio-libs/aiohttp#1925 (original issue, fix will be available in aiohttp>=4.0.0)

I will leave this issue open as an info for newcomers who face this issue also.

[gabbhack]

Also related: https://bugs.python.org/issue39232
Another workaround: encode/httpx#914 (comment)

[DenisNagornuyk]

It's worked!

[JrooTJunior]

Fixed in v3