python asyncio logger not logging aiohttp errors

Here is a python script that includes an async class which awaits a task and starts a background loop at initialization:

import asyncio, aiohttp, logging

logging.basicConfig(level=logging.DEBUG, filename='test.log', filemode='w')


class Client:

    async def _async_init(self):
        self.session = aiohttp.ClientSession()
        self.bg_task = asyncio.create_task(self._background_task())
        await self.make_request()
        logging.debug('async client initialized.')
        return self

    async def make_request(self):
        async with self.session.get('https://google.com') as response:
            self.info = await response.text()

    async def _background_task(self):
        while True:
            await asyncio.sleep(1000)


async def main():
    client = await Client()._async_init()
    # Intentionally leaving the aiohttp client session unclosed...
    # ...to log the 'unclosed client session' error.

asyncio.run(main())

Output (not desired):

# test.log

DEBUG:asyncio:Using proactor: IocpProactor
DEBUG:root:async client initialized.

What I want is to log certain asyncio errors to the test.log file. These errors normally get printed out to the terminal if I don’t use any logging. These errors are also logged on program exit since they are logged for unclosed client session and unclosed connector situations.

I figured that if I remove the background task from the class:

# These lines are removed from the class

...
# self.bg_task = asyncio.create_task(self._background_task())
...
# async def _background_loop(self):
#     while True:
#         await asyncio.sleep(1000)
...

Output (desired):

# test.log

DEBUG:asyncio:Using proactor: IocpProactor
DEBUG:root:async client initialized.
ERROR:asyncio:Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x000002043315D6D0>
ERROR:asyncio:Unclosed connector
connections: ['[(<aiohttp.client_proto.ResponseHandler object at 0x000002043312B230>, 44091.562)]', '[(<aiohttp.client_proto.ResponseHandler object at 0x000002043312B7E0>, 44092.468)]']
connector: <aiohttp.connector.TCPConnector object at 0x000002043315D710>

The question is, how can I get this output while also keeping the background task in the class?

It might be useful to note that I checked the aiohttp and asyncio sources. I saw that aiohttp calls asyncio’s call_exception_handler to log these errors and they are logged inside this method in asyncio library with a simple logger.error(). asyncio’s logger has no configurations made other than it’s name.

Why asyncio‘s exception handler is not called(?) due to my background task is beyond my understanding so it’d also be helpful to know if someone explains that part.