I have a multi module Android project. The :app: m...

# kapt

[Liam Heneghan]

I have a multi module Android project. The app module is mixed Kotlin and Java. I have KAPT incremental enabled. When I add a new private function to a ViewModel class KAPT appears to
process every source file in the app module despite being able to identify the changed file. Is this expected?

Android Gradle Plugin: 3.5.3
Kotlin version: 1.3.61
Gradle version: 5.6

Some KAPT verbose output:

[INFO] Kapt3 is enabled (stand-alone mode).
Annotation processing mode: apt
Memory leak detection mode: none
Show processor time: false
Verbose mode: true
Info as warnings: false
Use light analysis: false
Correct error types: false
Map diagnostic locations: false
Strict mode: false
Detect annotation processors in compile classpath: false
Incremental annotation processing (apt mode): true
Javac options: {-Xmaxerrs=500, -source=1.8}
[incremental apt] Changed files: [/path/to/file/changed/ViewModel.java] <- Correctly identifies changed file
[INFO] Processing java sources with annotation processors: [list of what looks like all source files in the app module]

Annotation processors in app module:

dagger.internal.codegen.ComponentProcessor
dagger.android.processor.AndroidProcessor
com.squareup.inject.assisted.dagger2.processor.AssistedInjectDagger2Processor
androidx.lifecycle.LifecycleProcessor
com.squareup.moshi.kotlin.codegen.JsonClassCodegenProcessor
butterknife.compiler.ButterKnifeProcessor
android.databinding.annotationprocessor.ProcessDataBinding
com.squareup.inject.assisted.processor.AssistedInjectProcessor

[Liam Heneghan]

There is a data module in the project which uses
moshi-kotlin-codegen and room-compiler - I can see from the kapt verbose logs that changing a class in this module processes only the changed file. So the issue I’m having seems specific to the app module.

I haven’t been able to find anything useful using a build scan or running gradle with --debug.

Is it possible to debug the kapt plugin as it runs on the project?

[Liam Heneghan]

I’ve also found that adding a new and unused class with no annotations triggers kapt to run again in the app module.