In an effort to further debug, I copied my entire emonhub.conf over from my prod emonpi. This contains a lot of devices of varying complexity
Oddly, some other devices work, with emonhub on piZ relaying correctly via MQTT.
The single value device (id 20) doesn’t work and crashes emonhub with the .copy() error when packets are received from it. When this entry is removed from emonhub.conf, I no longer get the .copy() error.
I’ll keep trying to hone in on what is causing this.