Error: cannot find symbol variable DaggerAppComponent

Seems like I was using the wrong dependencies:

compile 'com.google.dagger:dagger-android:2.x'
compile 'com.google.dagger:dagger-android-support:2.x' // if you use the support libraries
annotationProcessor 'com.google.dagger:dagger-android-processor:2.x'

The above dependencies should be used if you are using classes in dagger.android.

The correct dependencies are:

compile 'com.google.dagger:dagger:2.x'
annotationProcessor 'com.google.dagger:dagger-compiler:2.x'

You need these two lines

implementation 'com.google.dagger:dagger:2.16'
kapt 'com.google.dagger:dagger-compiler:2.16'

Use kapt instead of annotationProcessor when using kotlin. Generated class like Dagger+AppComponentClass, eg:DaggerAppComponent