Anvil 2x slower than Dagger

I recently added Anvil to a project, that had both Dagger and dagger-android (sigh), and I noticed 2x-3x clean/incremental build times .

I managed to repro it in a sample project. First commit of that PR uses Anvil, second commit uses Dagger to contribute a module to the AppComponent. Running gradlew --scan buildDegug for clean and incremental builds, in both commits yields the following:

with Anvil (1st commit)

• clean build -> https://gradle.com/s/bh7cxidxzkkc4
• incremental build -> https://gradle.com/s/mmcg6ee3wed4y

with Dagger (second commit)

• clean build -> https://scans.gradle.com/s/5tz6skgnhtxxa
• incremental build -> https://gradle.com/s/a75gqnc3uamcu

For the incremental builds, it seems that app:compileDebugKotlin is not incremental when using Anvil, I was not able to figure out why.

Note: To trigger incremental builds I just added a timber line into the Dummy#dummy method

[vRallev]

I don’t have any other recommendations. Like I said we only enable the Dagger annotation processor and Kapt in the final app module. Everywhere else we rely on Anvil to generate Dagger factories. We don’t use any other annotation processors. Because of that we saw a significant improvement in performance.

[aitorvs]

@vRallev thanks a lot. I have fixed the access to the sample project now.

I have run with :app:assembleDebug --info and it seems the task :app:compileDebugKotlin is incremental

Task ':app:compileDebugKotlin' is not up-to-date because:
  Input property 'classpath' file /Users/aitor/code/android-scaffolding/dummy/build/intermediates/compile_library_classes_jar/debug/classes.jar has changed.
Anvil: Incremental compilation enabled: true (compile)
Anvil: Use precise java tracking: false

However, when using anvil it takes a lot more time.

With dagger

Task ':app:compileDebugKotlin' is not up-to-date because:
  Input property 'classpath' file /Users/aitor/code/android-scaffolding/dummy/build/intermediates/compile_library_classes_jar/debug/classes.jar has changed.
Anvil: Incremental compilation enabled: true (compile)
Anvil: Use precise java tracking: false
...
...
:app:compileDebugKotlin (Thread[Execution worker for ':',5,main]) completed. Took 0.055 secs.

with anvil

Task ':app:compileDebugKotlin' is not up-to-date because:
  Input property 'classpath' file /Users/aitor/code/android-scaffolding/dummy/build/intermediates/compile_library_classes_jar/debug/classes.jar has changed.
Anvil: Incremental compilation enabled: true (compile)
Anvil: Use precise java tracking: false
...
...
:app:compileDebugKotlin (Thread[Execution worker for ':' Thread 11,5,main]) completed. Took 0.787 secs.

Could you shed some light as to why this happens?