ModuleProcessingStep/BindingMethodProcessingStep error when injecting classes from flavor specific directories (2.59.2)

[jamesscott-zaptec]

Hi,

We have been updating our app dependencies and had issues with specific builds; seeing compilation errors with ksp similar to many other issues raised in this library, however from what I've been able to reproduce we seem to be having a different issue.

I have pushed a sample project outlining a simple reproducible example, but I'll outline the findings here.

This project is using the following dependency versions:

agp = "9.0.1"
kotlin = "2.3.10"
ksp = "2.3.6"
google-dagger = "2.59.2"

We have an Android library module that supports our :app module. Both of these modules are configured to have flavors to allow us to produce different builds. A common pattern is to declare an interface in a common directory: /main and implement this differently in flavor-specific directories to change the app's behaviour based on build flavor selected.

If we choose to satisfy the dependency with an implementation defined in /main we do not see an issue and are able to successfully compile.

However, we have noticed providing an implementation from a flavor directory (e.g /myFlavorDebug) produces the following error:

> Task :support:kspDevCompleteDebugKotlin FAILED
e: [ksp] ModuleProcessingStep was unable to process 'com.zaptec.test.support.SupportModule' because 'MyClass' could not be resolved.

Dependency trace:
    => element (CLASS): com.zaptec.test.support.SupportModule
    => element (METHOD): provideMyInterface(MyClass)
    => element (PARAMETER): mClass
    => type (ERROR parameter type): MyClass

If type 'MyClass' is a generated type, check above for compilation errors that may have prevented the type from being generated. Otherwise, ensure that type 'MyClass' is on your classpath.
e: [ksp] BindingMethodProcessingStep was unable to process 'provideMyInterface(MyClass)' because 'MyClass' could not be resolved.

Dependency trace:
    => element (CLASS): com.zaptec.test.support.SupportModule
    => element (METHOD): provideMyInterface(MyClass)
    => element (PARAMETER): mClass
    => type (ERROR parameter type): MyClass

If type 'MyClass' is a generated type, check above for compilation errors that may have prevented the type from being generated. Otherwise, ensure that type 'MyClass' is on your classpath.

FAILURE: Build failed with an exception.

[bcorso]

@jamesscott-zaptec is this issue specific to KSP? In particular, do things work as expected if you switch to KAPT?