Android build faild

[Krosxx]

Describe the bug
Build error:

> Task :app:kaptGenerateStubsDebugKotlin FAILED
e: org.jetbrains.kotlin.backend.common.BackendException: Backend Internal error: Exception during IR lowering

To Reproduce
Steps to reproduce the behavior:

1. Kotlin 2.2.0
2. gradle: gradle-8.14.2-bin.zip, agp: 8.11.0
3. OS MacOS, Android project
4. Android Studio Narwhal | 2025.1.1
5. build.gradle.kts:

plugins {
    kotlin("plugin.serialization") version "2.2.0"
    id("org.jetbrains.kotlinx.rpc.plugin") version "0.8.0"
}

dependencies {
    ...
    implementation("io.ktor:ktor-client-cio-jvm:3.2.1")
    implementation("org.jetbrains.kotlinx:kotlinx-rpc-krpc-serialization-json:0.8.0")
    implementation("org.jetbrains.kotlinx:kotlinx-rpc-krpc-client:0.8.0")
    implementation("org.jetbrains.kotlinx:kotlinx-rpc-krpc-ktor-client:0.8.0")
}

6. Android Studio Plugin Installed: Kotlin External FIR Support (0.1.2)

7. Rpc Service Interface:

import kotlinx.rpc.annotations.Rpc

@Rpc
interface RpcService {
    suspend fun time(): Long
}

How can I solve this problem?

Expected behavior
Build Successed.

Additional context

Full error logs:

gradle: gradle-8.14.2-bin.zip
agp: 8.11.0
kotlin version: 2.2.0
error message: org.jetbrains.kotlin.backend.common.BackendException: Backend Internal error: Exception during IR lowering
File being compiled: .../app/src/main/java/x/x/rpc/RpcService.kt
The root cause java.lang.AssertionError was thrown at: org.jetbrains.kotlin.backend.jvm.lower.ObjectClassLowering.lower(ObjectClassLowering.kt:44)
	at org.jetbrains.kotlin.backend.common.BackendException$Companion.report(BackendException.kt:31)
	at org.jetbrains.kotlin.backend.common.BackendException$Companion.report$default(BackendException.kt:15)
	at org.jetbrains.kotlin.backend.common.phaser.PerformByIrFilePhase.invoke(PerformByIrFilePhase.kt:37)
	at org.jetbrains.kotlin.backend.common.phaser.PerformByIrFilePhase.invoke(PerformByIrFilePhase.kt:15)
	at org.jetbrains.kotlin.backend.common.phaser.PhaseEngine.runPhase(PhaseEngine.kt:64)
	at org.jetbrains.kotlin.backend.common.phaser.PhaseEngine.runPhase$default(PhaseEngine.kt:56)
	at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.invokeLowerings(JvmIrCodegenFactory.kt:359)
	at org.jetbrains.kotlin.cli.jvm.compiler.legacy.pipeline.JvmCompilerPipelineKt.generateCodeFromIr(jvmCompilerPipeline.kt:170)
	at org.jetbrains.kotlin.kapt.FirKaptAnalysisHandlerExtension.contextForStubGeneration(FirKaptAnalysisHandlerExtension.kt:223)
	at org.jetbrains.kotlin.kapt.FirKaptAnalysisHandlerExtension.doAnalysis(FirKaptAnalysisHandlerExtension.kt:117)
	at org.jetbrains.kotlin.fir.extensions.FirAnalysisHandlerExtension$Companion.analyze(FirAnalysisHandlerExtension.kt:29)
	at org.jetbrains.kotlin.cli.pipeline.jvm.JvmFrontendPipelinePhase.executePhase(JvmFrontendPipelinePhase.kt:84)
	at org.jetbrains.kotlin.cli.pipeline.jvm.JvmFrontendPipelinePhase.executePhase(JvmFrontendPipelinePhase.kt:56)
	at org.jetbrains.kotlin.cli.pipeline.PipelinePhase.phaseBody(PipelinePhase.kt:68)
	at org.jetbrains.kotlin.cli.pipeline.PipelinePhase.phaseBody(PipelinePhase.kt:58)
	at org.jetbrains.kotlin.config.phaser.NamedCompilerPhase.invoke(CompilerPhase.kt:102)
	at org.jetbrains.kotlin.backend.common.phaser.CompositePhase.invoke(PhaseBuilders.kt:22)
	at org.jetbrains.kotlin.config.phaser.CompilerPhaseKt.invokeToplevel(CompilerPhase.kt:53)
	at org.jetbrains.kotlin.cli.pipeline.AbstractCliPipeline.runPhasedPipeline(AbstractCliPipeline.kt:109)
	at org.jetbrains.kotlin.cli.pipeline.AbstractCliPipeline.execute(AbstractCliPipeline.kt:68)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecutePhased(K2JVMCompiler.kt:78)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecutePhased(K2JVMCompiler.kt:44)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:90)
	at org.jetbrains.kotlin.cli.common.CLICompiler.exec(CLICompiler.kt:352)
	at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunnerBase.runCompiler(IncrementalJvmCompilerRunnerBase.kt:175)
	at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunnerBase.runCompiler(IncrementalJvmCompilerRunnerBase.kt:38)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.doCompile(IncrementalCompilerRunner.kt:504)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileImpl(IncrementalCompilerRunner.kt:421)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileNonIncrementally(IncrementalCompilerRunner.kt:306)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compile(IncrementalCompilerRunner.kt:133)
	at org.jetbrains.kotlin.daemon.CompileServiceImplBase.execIncrementalCompiler(CompileServiceImpl.kt:679)
	at org.jetbrains.kotlin.daemon.CompileServiceImplBase.access$execIncrementalCompiler(CompileServiceImpl.kt:93)
	at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1802)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:586)
	at java.rmi/sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:360)
	at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:200)
	at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:197)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:784)
	at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:598)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:844)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:721)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:718)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:720)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
	at java.base/java.lang.Thread.run(Thread.java:1595)
Caused by: java.lang.AssertionError: Object should have a primary constructor: Companion
	at org.jetbrains.kotlin.backend.jvm.lower.ObjectClassLowering.lower(ObjectClassLowering.kt:44)
	at org.jetbrains.kotlin.backend.common.ClassLoweringVisitor.visitClass(Lower.kt:98)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitClass(IrVisitorVoid.kt:44)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitClass(IrVisitorVoid.kt:18)
	at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:72)
	at org.jetbrains.kotlin.ir.declarations.IrClass.acceptChildren(IrClass.kt:76)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptChildrenVoid(IrVisitors.kt:23)
	at org.jetbrains.kotlin.backend.common.ClassLoweringVisitor.visitClass(Lower.kt:97)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitClass(IrVisitorVoid.kt:44)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitClass(IrVisitorVoid.kt:18)
	at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:72)
	at org.jetbrains.kotlin.ir.declarations.IrClass.acceptChildren(IrClass.kt:76)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptChildrenVoid(IrVisitors.kt:23)
	at org.jetbrains.kotlin.backend.common.ClassLoweringVisitor.visitClass(Lower.kt:97)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitClass(IrVisitorVoid.kt:44)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitClass(IrVisitorVoid.kt:18)
	at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:72)
	at org.jetbrains.kotlin.ir.declarations.IrPackageFragment.acceptChildren(IrPackageFragment.kt:27)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptChildrenVoid(IrVisitors.kt:23)
	at org.jetbrains.kotlin.backend.common.ClassLoweringVisitor.visitElement(Lower.kt:93)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitPackageFragment(IrVisitorVoid.kt:168)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitFile(IrVisitorVoid.kt:184)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitFile(IrVisitorVoid.kt:180)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorVoid.visitFile(IrVisitorVoid.kt:18)
	at org.jetbrains.kotlin.ir.declarations.IrFile.accept(IrFile.kt:27)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptVoid(IrVisitors.kt:11)
	at org.jetbrains.kotlin.backend.common.LowerKt.runOnFilePostfix(Lower.kt:86)
	at org.jetbrains.kotlin.backend.common.ClassLoweringPass.lower(Lower.kt:58)
	at org.jetbrains.kotlin.backend.jvm.lower.ObjectClassLowering.lower(ObjectClassLowering.kt:31)
	at org.jetbrains.kotlin.backend.common.phaser.PhaseFactoriesKt.createFilePhase$lambda$4(PhaseFactories.kt:88)
	at org.jetbrains.kotlin.backend.common.phaser.PhaseBuildersKt$createSimpleNamedCompilerPhase$1.phaseBody(PhaseBuilders.kt:58)
	at org.jetbrains.kotlin.config.phaser.NamedCompilerPhase.invoke(CompilerPhase.kt:102)
	at org.jetbrains.kotlin.backend.common.phaser.PerformByIrFilePhase.invoke(PerformByIrFilePhase.kt:34)
	... 45 more

[Mr3zee]

Thanks! I will take a look

[Krosxx]

@Mr3zee Thanks for your reply. I referred to /samples/ktor-android-app and put @Rpc interface in the common module. This problem did not occur. However, this problem will occur as long as an @Rpc interface is declared in the app module.

[Mr3zee]

@Krosxx it seems that I can't reproduce this one.

However, this problem will occur as long as an @rpc interface is declared in the app module.

I did this, but everything compiles fine for me