K2 KAPT (aka KAPT4) doesn't like inline/reified.

[tinder-johnbuhanan2]

Kotlin 2.0.20-Beta2
Dagger 2.51.1

Apparently having an inline/reified inside one of the injecting classes breaks things.

I attached a small reproducing project:
Example.zip

[kuanyingchou]

Thanks for the report. The error seems to be from xprocessing, a library Dagger uses. Here's the stacktrace I got from the repro. This could happen if we're trying to call getDescriptor on a inline reified function, which may not have a descriptor in JVM, as it's not visible to Java.

Caused by: java.lang.NullPointerException
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.kotlin.KmFunctionContainerImpl.getDescriptor(KotlinClassMetadataUtils.kt:256)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.kotlin.KmClassContainer$functionByDescriptor$2.invoke(KotlinClassMetadataUtils.kt:147)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.kotlin.KmClassContainer$functionByDescriptor$2.invoke(KotlinClassMetadataUtils.kt:145)
	at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.kotlin.KmClassContainer.getFunctionByDescriptor(KotlinClassMetadataUtils.kt:145)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.kotlin.KmClassContainer.getFunctionMetadata(KotlinClassMetadataUtils.kt:142)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacMethodElement$kotlinMetadata$2.invoke(JavacMethodElement.kt:79)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacMethodElement$kotlinMetadata$2.invoke(JavacMethodElement.kt:78)
	at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacMethodElement.getKotlinMetadata(JavacMethodElement.kt:78)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacTypeElement.getSyntheticMethodsForAnnotations(JavacTypeElement.kt:217)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacFieldElement$syntheticMethodForAnnotations$2.invoke(JavacFieldElement.kt:59)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacFieldElement$syntheticMethodForAnnotations$2.invoke(JavacFieldElement.kt:57)
	at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacFieldElement.getSyntheticMethodForAnnotations(JavacFieldElement.kt:57)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacFieldElement.getAllAnnotations(JavacFieldElement.kt:43)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.XAnnotated.getAnnotations(XAnnotated.kt:39)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.XAnnotated.hasAnnotation(XAnnotated.kt:104)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.XAnnotated.hasAnyAnnotation(XAnnotated.kt:126)
	at dagger.internal.codegen.binding.InjectionAnnotations.hasInjectAnnotation(InjectionAnnotations.java:349)
	at dagger.internal.codegen.validation.InjectValidator.validateForMembersInjectionInternalUncached(InjectValidator.java:380)
	at dagger.internal.codegen.base.Util.reentrantComputeIfAbsent(Util.java:33)
	at dagger.internal.codegen.validation.InjectValidator.validateForMembersInjectionInternal(InjectValidator.java:369)
	at dagger.internal.codegen.validation.InjectValidator.validateUncached(InjectValidator.java:143)
	at dagger.internal.codegen.base.Util.reentrantComputeIfAbsent(Util.java:33)
	at dagger.internal.codegen.validation.InjectValidator.validate(InjectValidator.java:138)
	at dagger.internal.codegen.validation.InjectBindingRegistryImpl.tryRegisterConstructor(InjectBindingRegistryImpl.java:255)
	at dagger.internal.codegen.validation.InjectBindingRegistryImpl.tryRegisterInjectConstructor(InjectBindingRegistryImpl.java:241)
	at dagger.internal.codegen.processingstep.InjectProcessingStep.process(InjectProcessingStep.java:73)
	at dagger.internal.codegen.processingstep.TypeCheckingProcessingStep.lambda$process$0(TypeCheckingProcessingStep.java:94)
	at com.google.common.collect.RegularImmutableMap.forEach(RegularImmutableMap.java:297)
	at dagger.internal.codegen.processingstep.TypeCheckingProcessingStep.process(TypeCheckingProcessingStep.java:72)
	at dagger.internal.codegen.processingstep.TypeCheckingProcessingStep.process(TypeCheckingProcessingStep.java:49)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.XProcessingStep.process(XProcessingStep.kt:59)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.CommonProcessorDelegate.processRound(XBasicAnnotationProcessor.kt:132)
	at dagger.spi.internal.shaded.androidx.room.compiler.processing.javac.JavacBasicAnnotationProcessor.process(JavacBasicAnnotationProcessor.kt:73)
	at org.jetbrains.kotlin.kapt3.base.incremental.IncrementalProcessor.process(incrementalProcessors.kt:90)
	at org.jetbrains.kotlin.kapt3.base.ProcessorWrapper.process(annotationProcessing.kt:216)
	at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:1023)
	... 44 more

[tinder-johnbuhanan2]

Neat! Thank you for your attention. I feel good that y'all have everything handled.

[kuanyingchou]

This is due to an issue or behavior change in KAPT4. I'm making a workaround fix in an underlying library Dagger uses and it should be included in a future Dagger release.

[guuilp]

Hi @kuanyingchou! I've seen this fix didn't land on 2.52. Which release can we expect this fix?

[kuanyingchou]

Hi, @guuilp , 2.52 was released before the fix so please watch out for the next Dagger release, or alternatively You can try Kotlin 2.1.0-Beta1, which contains a different K2 KAPT implementation and should have fixed this.

[guuilp]

Awesome! I'll definitely give it a try, thanks for the tip!