@impy yes, they are source directories (tried a main function in 2 different modules, same result)
@ilya.gorbunov Thanks. Actually, checking module dependencies in Project Structure lists all my dependencies as Provided.
I'm on 2016.3.5.
Any workaround except manually changing every dependency?
Edit: someone on SO said the issue is related to gradle 3.4, and reverting to gradle 3.3 fixes it. Will try.
Edit: Gradle 3.3 fixes it. Thanks!