AttributeError: 'NoneType' object has no attribute 'sys_path'
This was already documented in https://github.com/libratbag/ratbag-emu but we should keep an issue here.
Basically, we are not pulling the udev events fast enough compared to the other hid and evdev events, meaning that you sometimes pull an event when UHIDDevice is not in a correct state.
What can be a band-aid is to not destroy the device too quickly. Either postpone the destroy at a later time or simply add a little bit of a delay right after the creation in your client. TLDR: I don't think this is something you can easily solve right now, and I really don't have the time today.
Related discussion: https://github.com/libratbag/ratbag-emu/pull/16