Could not get unknown property 'main' for SourceSet container of type org.gradle.api.internal.tasks.DefaultSourceSetContainer

Question

First, I'm simply trying to get AspectJ to pick up my compiled Kotlin classes. While trying to do this, I ran across a post that said the OP was able to get AspectJ to pick up Kotlin files by adding this to the end of their modules build.gradle:

sourceSets.main.output.classesDir = sourceSets.main.output.classesDir.toString().replace("java", "kotlin")

But that gives me an error:

Could not get unknown property 'main' for SourceSet container of type org.gradle.api.internal.tasks.DefaultSourceSetContainer.

I've tried adding the sourceSet main to the android DSL container, and all of the code lives in <module>/src/main/java/, so I'm really not sure what the deal is.

Answer 1

I'm having a hard time visualizing your project structure. However I was getting the same error recently (nothing to do with AspectJ though). The problem is that the main source set in sourceSets.main is unresolved within Android projects (it is a valid source set within Java projects, which is what I was copying my original code from). To fix this, I changed: sourceSets.main. to android.sourceSets.main. to reference the actual main source set within Android projects.

Let me know if this works out! And if it doesn't, consider maybe adding a bit more detail to how your project is set up?