The "ModuleProcessingStep was unable to process NetworkModule because
LibraryApi could not be resolved" failure under KSP2 + Hilt 2.59.2
turns out to be specific to @Provides returning a hand-written Kotlin
interface that carries no KSP-processed annotations. Hilt's
ModuleProcessingStep resolves the return type through KSP2's API and
gets an ERROR type for source-only interfaces in some configurations
(google/dagger#4303 cluster).
Two source-of-truth interfaces I tested side-by-side:
- AuthSessionDao (@Dao, Room-processed) — @Provides works
- LibraryApi (only @GET Retrofit annotations, no KSP processor) — fails
Workaround that's actually a better pattern: feature repositories
construct their Retrofit interface from the Hilt-injected shared
Retrofit instance. Fewer bindings in the Hilt graph; one Retrofit
interface lives next to its sole consumer.
LibraryApi.kt + wire types remain; LibraryRepository (Phase 5.2) will
hold the `retrofit.create<LibraryApi>()` call.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusenandClaude Opus 4.7
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