Sorry, python isn’t my first choice language. I’ve just added many self._log.info("line x") to the source until I worked out what was going on.
The ERROR MainThread 'available' is coming from src/emonhub.py:93
The exception is from EmonHubAutoConf(settings). I’m not really sure what’s going on in here, but the reason it was crashing, was that the hardcoded file /opt/openenergymonitor/emonhub/conf/available.conf was in my case symlinked to /etc/emonhub/emonhub.conf and did not contain the [available] header. I may have upgraded the source many times, and my config file was from an older version?
Anyway, fixed by copying the example conf/available.conf to that hard-coded location.
I don’t know how my installation config got in such a mess, but the debugging messages did not really help to identify that there was no [available] header in my emonhub.conf.