compiler plugin internal error: unable to transform declaration

[ewaldc]

Describe the bug

org.jetbrains.kotlin.backend.common.CompilationException: Back-end: Please report this problem https://kotl.in/issue
D:/Github/VirtuRun/app/src/main/java/com/eco/virtuRun/data/model/AppSettings.kt:43:1
Problem with `@Deprecated(message = "This synthesized declaration should not be used directly", replaceWith = ReplaceWith(expression = "", imports = []), level = DeprecationLevel.HIDDEN)
@StabilityInferred(parameters = 0)
object $serializer : GeneratedSerializer<AppSettings> {
  private constructor() /* primary */ {
    super/*Any*/()
    /* <init>() */

  }

  /* fake */ override operator fun equals(other: Any?): Boolean
  /* fake */ override fun hashCode(): Int
  /* fake */ override fun toString(): String
  /* fake */ override fun typeParametersSerializers(): Array<KSerializer<*>>
  override val descriptor: PluginGeneratedSerialDescriptor
    override get(): SerialDescriptor {
      return <this>.#descriptor
    }

  override fun childSerializers(): Array<KSerializer<*>>
  override fun deserialize(decoder: Decoder): AppSettings
  override fun serialize(encoder: Encoder, value: AppSettings) {
    val tmp0_desc: SerialDescriptor = <this>.<get-descriptor>()
    val tmp1_output: CompositeEncoder = encoder.beginStructure(descriptor = tmp0_desc)
    write$Self(self = value, output = tmp1_output, serialDesc = tmp0_desc)
    tmp1_output.endStructure(descriptor = tmp0_desc)
  }

  /* static final field */ val $stable: Int = LiveLiterals$AppSettingsKt.Int$class-$serializer$class-AppSettings()
  init {
    val tmp0_serialDesc: PluginGeneratedSerialDescriptor = PluginGeneratedSerialDescriptor(serialName = "com.eco.virtuRun.data.model.AppSettings", generatedSerializer = <this>, elementsCount = 8)
    tmp0_serialDesc.addElement(name = "persistableRepository", isOptional = false)
    tmp0_serialDesc.addElement(name = "settings", isOptional = false)
    tmp0_serialDesc.addElement(name = "userName", isOptional = true)
    tmp0_serialDesc.addElement(name = "vRunName", isOptional = true)
    tmp0_serialDesc.addElement(name = "speedMode", isOptional = true)
    tmp0_serialDesc.addElement(name = "intensity", isOptional = true)
    tmp0_serialDesc.addElement(name = "userList", isOptional = true)
    tmp0_serialDesc.addElement(name = "vRunList", isOptional = true)
    <this>.#descriptor = tmp0_serialDesc
  }

}

`
Details: kotlinx.serialization compiler plugin internal error: unable to transform declaration, see cause
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializerClassLowering.lower(SerializationLoweringExtension.kt:219)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:51)
	at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitClass(IrElementVisitorVoid.kt:111)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:64)
	at org.jetbrains.kotlin.ir.declarations.IrClass.acceptChildren(IrClass.kt:68)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptChildrenVoid(IrVisitors.kt:15)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:52)
	at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitClass(IrElementVisitorVoid.kt:111)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:64)
	at org.jetbrains.kotlin.ir.declarations.IrFile.acceptChildren(IrFile.kt:36)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptChildrenVoid(IrVisitors.kt:15)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitElement(SerializationLoweringExtension.kt:47)
	at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitPackageFragment(IrElementVisitorVoid.kt:190)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitPackageFragment(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitFile(IrElementVisitorVoid.kt:200)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitFile(IrElementVisitorVoid.kt:198)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlin.ir.declarations.IrFile.accept(IrFile.kt:30)
	at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptVoid(IrVisitors.kt:11)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt.runOnFileInOrder(SerializationLoweringExtension.kt:45)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtension.generate(SerializationLoweringExtension.kt:182)
	at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.convertToIr$lambda$0(JvmIrCodegenFactory.kt:190)
	at org.jetbrains.kotlin.psi2ir.Psi2IrTranslator.generateModuleFragment(Psi2IrTranslator.kt:107)
	at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.convertToIr(JvmIrCodegenFactory.kt:224)
	at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.convertToIr(JvmIrCodegenFactory.kt:57)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.convertToIr(KotlinToJVMBytecodeCompiler.kt:225)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:102)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli$default(KotlinToJVMBytecodeCompiler.kt:47)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:168)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:53)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:100)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:46)
	at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:101)
	at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunner.runCompiler(IncrementalJvmCompilerRunner.kt:495)
	at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunner.runCompiler(IncrementalJvmCompilerRunner.kt:133)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.doCompile(IncrementalCompilerRunner.kt:486)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileImpl(IncrementalCompilerRunner.kt:409)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileNonIncrementally(IncrementalCompilerRunner.kt:290)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compile(IncrementalCompilerRunner.kt:112)
	at org.jetbrains.kotlin.daemon.CompileServiceImplBase.execIncrementalCompiler(CompileServiceImpl.kt:627)
	at org.jetbrains.kotlin.daemon.CompileServiceImplBase.access$execIncrementalCompiler(CompileServiceImpl.kt:101)
	at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1587)
	at jdk.internal.reflect.GeneratedMethodAccessor108.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	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$1.run(Transport.java:197)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:712)
	at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:587)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:705)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:704)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.IndexOutOfBoundsException: Index 0 out of bounds for length 0
	at java.base/jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64)
	at java.base/jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70)
	at java.base/jdk.internal.util.Preconditions.checkIndex(Preconditions.java:266)
	at java.base/java.util.Objects.checkIndex(Objects.java:361)
	at java.base/java.util.ArrayList.get(ArrayList.java:427)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerIrGenerator$formEncodeDecodePropertyCall$1.invoke(SerializerIrGenerator.kt:340)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerIrGenerator$formEncodeDecodePropertyCall$1.invoke(SerializerIrGenerator.kt:333)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.BaseIrGenerator.serializerInstance(BaseIrGenerator.kt:440)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.BaseIrGenerator.formEncodeDecodePropertyCall(BaseIrGenerator.kt:255)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerIrGenerator.formEncodeDecodePropertyCall(SerializerIrGenerator.kt:333)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerIrGenerator$generateLoad$1.invoke(SerializerIrGenerator.kt:434)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerIrGenerator$generateLoad$1.invoke(SerializerIrGenerator.kt:368)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.IrBuilderWithPluginContext.addFunctionBody(IrBuilderWithPluginContext.kt:41)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerIrGenerator.generateLoad(SerializerIrGenerator.kt:368)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerIrGenerator.generate(SerializerIrGenerator.kt:617)
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerIrGenerator$Companion.generate(SerializerIrGenerator.kt:647)
	at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializerClassLowering.lower(SerializationLoweringExtension.kt:135)
	... 63 more

Errors were stored into D:\Github\VirtuRun\.gradle\kotlin\errors\errors-1689520564144.log

To Reproduce

@Serializable
data class AppSettings (
    var userName: String = "System",
    var vRunName: String = "System Run",
    var speedMode: vRunSpeedMode = vRunSpeedMode.VRUN_SPEED,
    var intensity: WorkoutIntensity = WorkoutIntensity.MODERATE,
    @Transient var favDevices: MutableMap<String, ScannedDevice> = mutableMapOf(), // Favorite devices
    var userList: MutableMap<String, User> = mutableMapOf(),
    var vRunList: MutableMap<String, VRun> = mutableMapOf()
) : Persistable<AppSettings>()

@OptIn(ExperimentalSerializationApi::class)
@Serializable
open class Persistable<T: Any> { 
    @EncodeDefault(EncodeDefault.Mode.NEVER) private lateinit var persistableRepository: PersistableRepository<T> //? = null
    @EncodeDefault(EncodeDefault.Mode.NEVER) private lateinit var settings: T //? = null
    operator fun invoke(initialValues: T, persistableRepository: PersistableRepository<T>) : T {
        this.persistableRepository = persistableRepository
        settings = persistableRepository.load() ?: initialValues
        return settings
    }
    fun save(): T = persistableRepository.save(settings)
}

interface PersistableRepository<T> {
    fun save(settings: T): T
    fun load(): T?
}

// Koin 
val appSettingsRepositoryModule = module {
    single { AppSettings()(AppSettings(), PersistableFileRepository(androidContext(), "app_settings.json", AppSettings.serializer())) }
}

removing lateinit by initializing both variables to null and/or removing @EncodeDefault does not change anything.

My objective is to create a "generic settings extension" for data classes which allows to load and save the class data locally and remotely.
Maybe I used the wrong approach and there are better ways to achieve this.

My project is very large, but if needed I can create a "working" project version on my github account.

Expected behavior
Compiles correctly (no lint issues)

Environment

• Kotlin version: 1.8.21 and 1.8.22
• Library version: 1.5.0 and 1.5.1
• Kotlin platforms: Android (JVM)
• Gradle version: 7.5
• IDE version: Android Studio Flamingo | 2022.2.1 Patch 2
• Other relevant context: JAVA 17

[ewaldc]

I published a small piece of code for Android 10+ that replicates the issue.
Code which is working fine
This contains a working, non-generic version using AppSettings, a data class that is being loaded (deserialize) and saved (serialized) to Android project data files in the Json format.
Code which causes the described issue
This is my attempt to recode this using generics.

Please note that I am new to Kotlin but experienced in C++/C#/C and other languages, for which I coded such functionality without issues.
But in Kotlin I hit several issues such as creating a serializer for Generic<T>, instantiating T() etc.

[ewaldc]

Ah, I think I found what is causing the error. The parameters of Persitable<T> should be marked protected rather than private and then it compiles OK. In addition, making Persitable<T> not @Serializable compiles OK too, which is even better as the superclass does not need to be serialized at all.
I will still leave the issue open as it is IMHO still advisible to have the compiler provide a meaningfull error rather than a crash, in line with what the error message says: "Please report this problem..."

[sandwwraith]

Yeah, you're right, this isn't what is supposed to happen. Given that the cause of error is a private val, I think it is similar to #2241. As a workaround you can make it protected or internal.