[KSP] After migrating to ksp Assisted Inject factory implementations cannot be found during incremental compilation

[AradiPatrik]

As title says. I am using assisted inject, and after upgrading to KSP my incremental compilation is broken and have to do clean builds every time. I get the error below

android gradle: "com.android.tools.build:gradle:8.1.1"
gradle plugin: "org.jetbrains.kotlin:kotlin-gradle-plugin:1.9.0"
ksp version: 1.9.0-1.0.13
dagger version: 2.48

gradle info

------------------------------------------------------------
Gradle 8.3-rc-2
------------------------------------------------------------

Build time:   2023-07-26 15:20:39 UTC
Revision:     c48101dc7f9c766efa8206574aa9c2195d2b7960

Kotlin:       1.9.0
Groovy:       3.0.17
Ant:          Apache Ant(TM) version 1.10.13 compiled on January 4 2023
JVM:          17.0.8 (JetBrains s.r.o. 17.0.8+7-b1000.8)
OS:           Mac OS X 13.0 aarch64

cannot find symbol
import my.package.impl.faceselector.screen.model.FaceSelectorScreenViewModel_Factory_Impl;
                                                ^
  symbol:   class FaceSelectorScreenViewModel_Factory_Impl
  location: package my.package.impl.faceselector.screen.model

[bcorso]

Hi @AradiPatrik, can you share a minimal reproducible example? AFAIK, we've done everything on Dagger's side to make this work, so it may be a bug in KSP.

[tevjef]

@bcorso A reproducer of this bug is in this repo/branch and here is a github action run with the failure.

/home/runner/work/android-bugs/android-bugs/app/build/generated/ksp/debug/java/com/company/myapplication/DaggerComponent.java:65: error: cannot find symbol

> Task :app:compileDebugJavaWithJavac FAILED
      this.factoryProvider = BugDemonstration_Factory_Impl.create(bugDemonstrationProvider);
                             ^
  symbol:   variable BugDemonstration_Factory_Impl
  location: class ComponentImpl
1 error

Workaround: Making the @AssistedFactory interface a top-level class seems to work.

I have been running into other incremental compilation issues that I haven't been able to reproduce and will revert to kapt until dagger ksp is in a more stable space.

[AradiPatrik]

@tevjef Thanks for the repro! For me this issue is sometimes still present after clean build. The only way to work around the issue is actually delete a line in the generated file (referencing the factory), and rebuild the project.

[bcorso]

@tevjef thanks for the repro. We're currently working with KSP team to figure out if this is an issue in Dagger, KSP, or Gradle. There's a few similar issues (#4063, #4060) and we have a couple repros now. I'll update again once we figure out what the fix needs to be.

[bcorso]

A quick update on this -- this appears to be an issue with how KSP exposes its output cache during incremental processing. I've filed a bug with the KSP team here: google/ksp#1555.

In the meantime, it is possible to workaround this issue in Dagger until the issue gets resolved in KSP. We should have the fix out this week and hopefully do a release as well.