Then there’s also another Kapt warning which I can’t resolve

w: [kapt] Sources output directory is not specified for database_debug, skipping annotation processing

The project builds fine, though. It’s a problem for us, because we’d like to make Kotlin compiler warnings errors with 1.2.

This Kapt warning makes me thing that you're applying kapt plugin but don't have any annotation processors in the module

I’m using the Room annotation processor. So there’s definitely one annotation processor