Unexpected suppressing of asyncio.CancelledError exception

[decaz]

• Initially raised as discussion Unexpected suppressing of asyncio.CancelledError exception #2370

Environment:

• Python 3.10.7
• httpx 0.23.0

Listing:

import asyncio

import httpx


async def request(url):
    async with httpx.AsyncClient() as client:
        try:
            await client.get(url)
        except BaseException as exc:
            print('Request exception', type(exc), exc)
            raise


async def main():
    url = 'http://1.2.3.4:1234/'  # Some unreachable resource with delay
    task = asyncio.create_task(request(url))
    await asyncio.sleep(1)
    task.cancel()
    try:
        await task
    except BaseException as exc:
        print('Task exception', type(exc), exc)


asyncio.run(main())

Expected behavior:

Request exception <class 'asyncio.exceptions.CancelledError'> 
Task exception <class 'asyncio.exceptions.CancelledError'> 

Actual behavior:

Request exception <class 'httpx.ConnectError'> All connection attempts failed
Task exception <class 'httpx.ConnectError'> All connection attempts failed

[tomchristie]

Answered on the discussion. Thanks for the prompt.

[decaz]

@tomchristie I guess the issue should be reopened due to the discussion evolve:

So the problem is there is no certainty which exception will be raised by httpx on cancellation of ongoing request.

Originally posted by @decaz in #2370 (reply in thread)

[tomchristie]

Let's continue this on #2370