After I upgraded from debian jessie to stretch, twistd does not find my plugin anymore. I could not find what's wrong. I guess I need to specify some path now which wasn't neccessary before or similar.
I get the error /usr/bin/twistd: Unknown command: otfbot
and in the list of Commands, the two commands of the software are not listed anymore. The directory structure of the plugins for twisted is
twisted/plugins/genconfig_plugin.py
twisted/plugins/otfbot_plugin.py
And both instantiate a ServiceMaker.