Cancelled tasks not being taken into account in connection pool's aclose

[hvmptydvmpty]

hi, i've a question about httpx/httpcore, specifically a RuntimeError raised by httpcore.AsyncConnectionPool.aclose method. i issue multiple GET requests to an API and if one of them fails i'd like to cancel any that are still in flight. when i cancel corresponding tasks (and even include them in asyncio.gather call) I then get the exception (httpcore._async.connection_pool) because requests_still_in_flight is True. Could someone please suggest a solution that both cancels pending requests and cleanly closes httpx.AsyncClient and the embedded connection pool? If there isn't one, perhaps requests_still_in_flight could be adjusted to include only requests that are not in cancelled (but undone) state, since closing connection pool will presumably close active TCP connection(s) and thereby follow the protocol?

I checked discussions #2138 and #2093 and the difference is that I actually do call .cancel() on all remaining tasks if one of them errors out, but still get exception.

General idea of the code is like this

async def func(it, cb):
  sem = asyncio.semaphore(10)
  tasks, exceptions = set(), []
  def _done(task):
    sem.release()
    tasks.remove(task)
    if task.exception():
      exceptions.append(task.exception())
  with httpx.AsyncClient() as client:
    for item in it:
      await sem.acquire()
      task = loop.create_task(cb(item, client))
      task.add_done_callback(_done)
      if exceptions:
        break
    for task in list(tasks):
      if task.done():
        tasks.remove(task)
      else:
        if exceptions:
          task.cancel()
    asyncio.gather(*tasks)
    # exception happens here