Custom component device_trigger.py methods aren't called?

Development
1

I added device_trigger.py as described here to my custom component: Device Triggers | Home Assistant Developer Docs (home-assistant.io)

However the file is never loaded and the contained methods never get called. I see a github issue for HA core that said exactly the same thing back in 2020 that was resolved completed with ‘Not all features are available for custom components at this moment in time.’.

Is it still impossible for custom components to have device triggers?

2

Found the problem. A bad import directive in the file causes it to silently not be loaded. There’s no error in the log to indicate a problem unlike a syntax error in the code.