Traceback on Firefox when Failing Connect

[wmorgansoftware]

I'm trying to fail a connection for login purposes, and the resulting action is successful, but when doing this in Firefox, I'm getting the following traceback in my server log:

Error on request:
Traceback (most recent call last):
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/async_drivers/threading.py", line 36, in wait
return self.ws.receive()
File "[path-to-project]/venv/lib/python3.10/site-packages/simple_websocket/ws.py", line 112, in receive
raise ConnectionClosed(self.close_reason, self.close_message)
simple_websocket.ws.ConnectionClosed: Connection closed: 1005

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "[path-to-project]/venv/lib/python3.10/site-packages/werkzeug/serving.py", line 335, in run_wsgi
execute(self.server.app)
File "[path-to-project]/venv/lib/python3.10/site-packages/werkzeug/serving.py", line 322, in execute
application_iter = app(environ, start_response)
File "[path-to-project]/venv/lib/python3.10/site-packages/flask/app.py", line 2548, in call
return self.wsgi_app(environ, start_response)
File "[path-to-project]/venv/lib/python3.10/site-packages/flask_socketio/init.py", line 43, in call
return super(_SocketIOMiddleware, self).call(environ,
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/middleware.py", line 63, in call
return self.engineio_app.handle_request(environ, start_response)
File "[path-to-project]/venv/lib/python3.10/site-packages/socketio/server.py", line 605, in handle_request
return self.eio.handle_request(environ, start_response)
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/server.py", line 411, in handle_request
packets = socket.handle_get_request(
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/socket.py", line 103, in handle_get_request
return getattr(self, 'upgrade' + transport)(environ,
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/socket.py", line 158, in _upgrade_websocket
return ws(environ, start_response)
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/async_drivers/threading.py", line 23, in call
return self.app(self)
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/socket.py", line 179, in _websocket_handler
pkt = websocket_wait()
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/socket.py", line 163, in websocket_wait
data = ws.wait()
File "[path-to-project]/venv/lib/python3.10/site-packages/engineio/async_drivers/threading.py", line 38, in wait
raise IOError()
OSError

Any ideas on how to not have this? I do not receive a traceback like this with Chromium.

[miguelgrinberg]

What version of Werkzeug do you have? Upgrade to the latest to make sure, there used to be a bug with the early 2.x releases that caused this.

[wmorgansoftware]

A quick pip list shows I am on version 2.2.2 of Werkzeug.

[miguelgrinberg]

I cannot reproduce here with the example app in this repository and the latest Werkzeug.

[wmorgansoftware]

Which test, if any, are you returning False or raising the connection refused error from your documentation on the connect event? That's where I'm seeing it, and I don't see a path for that in the example code.

[miguelgrinberg]

Sorry, I misunderstood. I missed the fact that you are failing the connection on purpose. I'll need to debug this, the IOError exception is actually correct, but it should have been caught and silenced, so probably the timing in which Firefox closes is a little different and I'm missing a catch somewhere along the error path.

In the meantime it is safe to ignore this exception, as it is not indicative of a problem.