granian 2.0.0 and prometheus_fastapi_instrumentator : Future object is not initialized.

[dalf]

See https://github.com/dalf/test_granian

• dependencies:

  fastapi==0.115.8
  prometheus-fastapi-instrumentator==7.0.2
  granian==2.0.0
  

• code:

  from fastapi import FastAPI
  
  from prometheus_fastapi_instrumentator import Instrumentator
  
  app = FastAPI(docs_url="/")
  
  instrumentator = Instrumentator().instrument(app)
  instrumentator.expose(app)

• command:

  granian t.py --interface asgi --task-impl asyncio

With granian 2.0.0 I have this error with Python 3.13, 3.12 and 3.11 :

[ERROR] Application callable raised an exception
Traceback (most recent call last):
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/granian/_futures.py", line 15, in future_watcher
    await inner(watcher.scope, watcher.proto)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/fastapi/applications.py", line 1054, in __call__
    await super().__call__(scope, receive, send)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/applications.py", line 112, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/middleware/errors.py", line 187, in __call__
    raise exc
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/middleware/errors.py", line 165, in __call__
    await self.app(scope, receive, _send)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/prometheus_fastapi_instrumentator/middleware.py", line 174, in __call__
    raise exc
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/prometheus_fastapi_instrumentator/middleware.py", line 172, in __call__
    await self.app(scope, receive, send_wrapper)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/middleware/exceptions.py", line 62, in __call__
    await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    raise exc
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/routing.py", line 715, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/routing.py", line 735, in app
    await route.handle(scope, receive, send)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/routing.py", line 288, in handle
    await self.app(scope, receive, send)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/routing.py", line 76, in app
    await wrap_app_handling_exceptions(app, request)(scope, receive, send)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    raise exc
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/routing.py", line 73, in app
    response = await f(request)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/fastapi/routing.py", line 301, in app
    raw_response = await run_endpoint_function(
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/fastapi/routing.py", line 214, in run_endpoint_function
    return await run_in_threadpool(dependant.call, **values)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/starlette/concurrency.py", line 37, in run_in_threadpool
    return await anyio.to_thread.run_sync(func)
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/anyio/to_thread.py", line 56, in run_sync
    return await get_async_backend().run_sync_in_worker_thread(
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/anyio/_backends/_asyncio.py", line 2428, in run_sync_in_worker_thread
    root_task = find_root_task()
  File "/home/dalf/code/test_granian/.venv/lib/python3.13/site-packages/anyio/_backends/_asyncio.py", line 316, in find_root_task
    for task in all_tasks():
  File "/home/dalf/.rye/py/[email protected]/lib/python3.13/asyncio/tasks.py", line 68, in all_tasks
    if futures._get_loop(t) is loop and not t.done()}
  File "/home/dalf/.rye/py/[email protected]/lib/python3.13/asyncio/futures.py", line 306, in _get_loop
    return get_loop()
RuntimeError: Future object is not initialized.

granian 1.7.6 and uvicorn, /metrics works fine. I'm not sure if I'm oversight something or if it highlight a bug in prometheus-fastapi-instrumentator or if there is a bug in granian.

[gi0baro]

@dalf wether 1.7.6 installs uvloop, in 2.0 is an optional dep. Can you confirm you're running with uvloop on 2.0, and if not, check if it works?

[dalf]

Yes, same error with uvloop

rye run granian --interface asgi --task-impl asyncio src/test_granian/__main__.py --loop uvloop

[gi0baro]

Let's move the conversation in #513