ValueError: list.remove(x): x not in list

[dimaqq]

Apologies for a not-very-well-formed bug report.

I was only able to hit this under rather weird conditions (streaming responses, backpressure, connection pool full).

ERROR:hypercorn.error:Error in ASGI Framework
Traceback (most recent call last):
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpcore/_async/connection_pool.py", line 227, in handle_async_request
    connection = await status.wait_for_connection(timeout=timeout)
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpcore/_async/connection_pool.py", line 34, in wait_for_connection
    await self._connection_acquired.wait(timeout=timeout)
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpcore/_synchronization.py", line 38, in wait
    await self._event.wait()
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 1842, in wait
    if await self._event.wait():
  File "/usr/local/lib/python3.10/asyncio/locks.py", line 214, in wait
    await fut
asyncio.exceptions.CancelledError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/hypercorn/asyncio/task_group.py", line 23, in _handle
    await app(scope, receive, send, sync_spawn, call_soon)
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/hypercorn/app_wrappers.py", line 33, in __call__
    await self.app(scope, receive, send)
  File "/home/proxy/proxy/app.py", line 119, in app
    async with config.upstream_client.stream(
  File "/usr/local/lib/python3.10/contextlib.py", line 199, in __aenter__
    return await anext(self.gen)
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1570, in stream
    response = await self.send(
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1614, in send
    response = await self._send_handling_auth(
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1642, in _send_handling_auth
    response = await self._send_handling_redirects(
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1679, in _send_handling_redirects
    response = await self._send_single_request(request)
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1716, in _send_single_request
    response = await transport.handle_async_request(request)
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpx/_transports/default.py", line 353, in handle_async_request
    resp = await self._pool.handle_async_request(req)
  File "/home/proxy/.cache/pypoetry/virtualenvs/proxy-9E6wT_fw-py3.10/lib/python3.10/site-packages/httpcore/_async/connection_pool.py", line 233, in handle_async_request
    self._requests.remove(status)
ValueError: list.remove(x): x not in list

At the very end, when httpcore fails here:

httpcore/httpcore/_async/connection_pool.py

Lines 228 to 234 in 5e06a9b

	except BaseException as exc:
	# If we timeout here, or if the task is cancelled, then make
	# sure to remove the request from the queue before bubbling
	# up the exception.
	async with self._pool_lock:
	self._requests.remove(status)
	raise exc

[dimaqq]

Versions:

• Python 3.10.5, Linux
• httpcore 0.15.0 A minimal low-level HTTP client.
• httpx 0.23.0 The next generation HTTP client.

[Tunglies]

Some example code would be useful.

[dimaqq]

I don't have an MRE, as this is relatively rare and happens in prod under unusual conditions.
Maybe I can copy-paste the user code that seems relevant.

[dimaqq]

    async with AsyncClient(
        proxies=...,  # using a SOCKS5 proxy from `httpx[socks]`
        limits=Limits(max_connections=...),
        timeout=...,
        cookies=...,
    ) as config.upstream_client:

# ...

        async with config.upstream_client.stream(method, str(url), headers=..., content=...) as resp:
            ...
            response = StreamingResponse(resp.aiter_bytes(), status_code=..., headers=...)
            ...
            await response(scope, receive, send)

[tomchristie]

Closed via #680