Starlette 0.36.0: KeyError 'extensions'

[akshayka]

I recently upgraded to starlette 0.36.0, and my app now fails to start with the following stack trace (I'm using uvicorn 0.27.0). I don't have a minimal reproduction right now (I'm sorry!), but any guidance as to whether this is a bug in my code or in the latest version of starlette would be appreciated.

ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/uvicorn/protocols/http/h11_impl.py", line 404, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 84, in __call__
    return await self.app(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/applications.py", line 123, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/errors.py", line 186, in __call__
    raise exc
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/errors.py", line 164, in __call__
    await self.app(scope, receive, _send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/cors.py", line 91, in __call__
    await self.simple_response(scope, receive, send, request_headers=headers)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/cors.py", line 146, in simple_response
    await self.app(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/exceptions.py", line 62, in __call__
    await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 64, in wrapped_app
    raise exc
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    await app(scope, receive, sender)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 758, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 778, in app
    await route.handle(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 487, in handle
    await self.app(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 758, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 778, in app
    await route.handle(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 487, in handle
    await self.app(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/staticfiles.py", line 104, in __call__
    await response(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/responses.py", line 340, in __call__
    elif "http.response.pathsend" in scope["extensions"]:
KeyError: 'extensions'
ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/uvicorn/protocols/http/h11_impl.py", line 404, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 84, in __call__
    return await self.app(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/applications.py", line 123, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/errors.py", line 186, in __call__
    raise exc
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/errors.py", line 164, in __call__
    await self.app(scope, receive, _send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/cors.py", line 83, in __call__
    await self.app(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/middleware/exceptions.py", line 62, in __call__
    await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 64, in wrapped_app
    raise exc
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    await app(scope, receive, sender)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 758, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 778, in app
    await route.handle(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 487, in handle
    await self.app(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 758, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 778, in app
    await route.handle(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 299, in handle
    await self.app(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 79, in app
    await wrap_app_handling_exceptions(app, request)(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 64, in wrapped_app
    raise exc
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    await app(scope, receive, sender)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/routing.py", line 77, in app
    await response(scope, receive, send)
  File "/home/akshay/envs/tmpenv/lib/python3.10/site-packages/starlette/responses.py", line 340, in __call__
    elif "http.response.pathsend" in scope["extensions"]:
KeyError: 'extensions'

[alangenfeld]

Getting reports of the same issue dagster-io/dagster#19356

[Kludex]

I'll release 0.36.1 shortly. Thanks.