Handling usocket errors

[JoeCharlieH]

While debugging a simple MQTT client device, I've encounter many headaches trying to catch the specific error that stopped the execution of my main program. After many attempts (and reading the usockets documentation and the lwip.c module), I learned the hard way that you need to sacrifice "Knowing that my device is always connected" for closing a socket.

My main question is, does these lwip error codes relate to the OSError code values raised by the usocket.py library?