Module 'test-a':

public final class A {
  @Inject A() {}
}

@Component
public interface ComponentA {
  A a();
}

Module 'test-b' which has implementation project(':test-a'):

public final class B {
  @Inject B(A a) {}
}

@Component(dependencies = ComponentA.class)
public interface ComponentB {
  B b();
}

Module 'test-c' which has implementation project(':test-b'):

public final class C {
  @Inject C(B b) {}
}

@Component(dependencies = ComponentB.class)
public interface ComponentC {
  C c();
}

fails with:

> Task :test-c:compileDebugJavaWithJavac FAILED
error: cannot access ComponentA
  class file for test.a.ComponentA not found
  Consult the following stack trace for details.
  com.sun.tools.javac.code.Symbol$CompletionFailure: class file for test.a.ComponentA not found
1 error

which makes sense, because 'test-c' isn't meant to see 'test-a' as it's an implementation detail of 'test-b', but why is Dagger in 'test-c' trying to do anything with ComponentA? Once it reaches ComponentB and sees the required B type exposed shouldn't it stop?