AGP 9.0 requirement is non-obvious and DX is confusing

[TWiStErRob]

I got this error on my CI for a minor update of dagger:

* What went wrong:
A problem occurred evaluating root project '...'.
> A problem occurred configuring project ':app'.
   > Failed to notify project evaluation listener.
      > com/android/build/api/artifact/ScopedArtifact$POST_COMPILATION_CLASSES
      > Task with name 'connectedDebugAndroidTest' not found in project ':app'.

it is really confusing, without stack trace I have no clue what's going on, and additionally that connectedDebugAndroidTest problem is very misleading (2nd part is likely project specific though, but clearly attributable to Dagger update).

After adding --stacktrace, from the root cause I can deduce that something has changed in dagger/hilt plugin, but still not clear what until blaming those lines:

Cause 1: java.lang.NoClassDefFoundError: com/android/build/api/artifact/ScopedArtifact$POST_COMPILATION_CLASSES
	at dagger.hilt.android.plugin.HiltGradlePlugin.createHiltCompileOnlyConfiguration(HiltGradlePlugin.kt:256)
	at dagger.hilt.android.plugin.HiltGradlePlugin.configureAggregatingTask$lambda$26(HiltGradlePlugin.kt:204)
	at dagger.hilt.android.plugin.util.VariantsKt$onAllVariants$1.invoke(Variants.kt:55)
	at dagger.hilt.android.plugin.util.VariantsKt$onAllVariants$1.invoke(Variants.kt:54)

[bcorso]

I got this error on my CI for a minor update of dagger:

I'm assuming this is after upgrading to Dagger 2.59?

Note that "Dagger 2" doesn't really follow semantic versioning that strictly. In fact, it has never had a major version change since the repo was initially forked from Square's Dagger 1. Thus, minor versions are what we use even for breaking changes.

After adding --stacktrace, from the root cause I can deduce that something has changed in dagger/hilt plugin, but still not clear what until blaming those lines:

Yeah, I get that it can be confusing. I tried to make it clear in the Dagger 2.58 and Dagger 2.59 release notes that AGP 9 is now a requirement, but maybe we can do better by adding a runtime check with a clearer error message.

Just to clarify, the issue does go away after you upgrade to AGP 9, right?

[TWiStErRob]

I'm assuming this is after upgrading to Dagger 2.59?

Yep, it's a Renovate PR from 2.58 to 2.59.

Note that Renovate can't find the release notes (probably because the dependency doesn't declare a source repository). And because I assumed minor, I thought it was safe and didn't think to research release notes to begin with.

but maybe we can do better by adding a runtime check with a clearer error message.

Why I opened this issue :)

Just to clarify, the issue does go away after you upgrade to AGP 9, right?

Haven't tried it yet, it's non-obvious in that project.

[GrakovNe]

I can confirm that upgrading to AGP 9 resolves the issue.

In my case, the Dagger/Hilt failure after updating from 2.58 → 2.59 was fully fixed once the project was migrated to AGP 9 with the required related changes.

For reference, here is a concrete example of an AGP 9 migration that unblocks Dagger 2.59:
GrakovNe/lissen-android@28cfd19

This aligns with the ScopedArtifact.POST_COMPILATION_CLASSES failure, which is no longer present once AGP 9 APIs are in place.