How make work werkzeug / custom error pages with flask + Gevent-socketio
I've recently solved this, Werkzeug debuggger can be modified to work with socket.io namespaces (and auto-reloading will also work), see here and enjoy:
To see werkzeug debugger you must serve all http request by default server with standart middleware stack.
But you launched separate SocketIOServer for serve websockets requests.