Hello, I am trying to add kotlinx rpc in my app, b...

# kotlinx-rpc

[Dragos Rachieru]

Hello, I am trying to add kotlinx rpc in my app, but it fails to compile, details in thread.

[Dragos Rachieru]

java.lang.NoClassDefFoundError: org/jetbrains/kotlinx/serialization/compiler/fir/SerializationFirResolveExtension
	at kotlinx.rpc.codegen.FirRPCServiceGenerator.<init>(FirRPCServiceGenerator.kt:84)
	at kotlinx.rpc.codegen.FirRPCExtensionRegistrar.configurePlugin$lambda$0(FirRPCExtensionRegistrar.kt:17)
	at org.jetbrains.kotlin.fir.extensions.FirExtensionService.registerExtensions(FirExtensionService.kt:43)
	at org.jetbrains.kotlin.fir.extensions.FirExtensionRegistrarKt.registerExtensions(FirExtensionRegistrar.kt:285)
	at org.jetbrains.kotlin.fir.session.FirSessionConfigurator.configure(FirSessionConfigurator.kt:53)
	at org.jetbrains.kotlin.fir.session.FirAbstractSessionFactory.createModuleBasedSession(FirAbstractSessionFactory.kt:119)
	at org.jetbrains.kotlin.fir.session.FirJvmSessionFactory.createModuleBasedSession(FirJvmSessionFactory.kt:102)
	at org.jetbrains.kotlin.cli.common.FirSessionConstructionUtilsKt.prepareJvmSessions(FirSessionConstructionUtils.kt:87)
	at org.jetbrains.kotlin.cli.jvm.compiler.pipeline.JvmCompilerPipelineKt.compileModuleToAnalyzedFir(jvmCompilerPipeline.kt:292)
	at org.jetbrains.kotlin.cli.jvm.compiler.pipeline.JvmCompilerPipelineKt.compileModulesUsingFrontendIrAndLightTree(jvmCompilerPipeline.kt:115)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:155)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:50)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:104)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:48)
	at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:101)
	at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunner.runCompiler(IncrementalJvmCompilerRunner.kt:453)
	at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunner.runCompiler(IncrementalJvmCompilerRunner.kt:62)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.doCompile(IncrementalCompilerRunner.kt:506)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileImpl(IncrementalCompilerRunner.kt:423)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileNonIncrementally(IncrementalCompilerRunner.kt:301)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compile(IncrementalCompilerRunner.kt:129)
	at org.jetbrains.kotlin.daemon.CompileServiceImplBase.execIncrementalCompiler(CompileServiceImpl.kt:676)
	at org.jetbrains.kotlin.daemon.CompileServiceImplBase.access$execIncrementalCompiler(CompileServiceImpl.kt:92)
	at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1661)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	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:840)
Caused by: java.lang.ClassNotFoundException: org.jetbrains.kotlinx.serialization.compiler.fir.SerializationFirResolveExtension
	at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:445)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:592)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
	... 41 more

[Dragos Rachieru]

This is the folder that contains the RPC code.

https://github.com/dragossusi/ktcnc/tree/develop/backend/rpc

[Alexander Sysoev]

Hi! What kotlin version do you use and have you added serialization plugin?

[Dragos Rachieru]

2.0.10

[Dragos Rachieru]

plugins {
kotlin("multiplatform")
kotlin("plugin.serialization")
id("io.ktor.plugin")
id("org.jetbrains.kotlinx.rpc.plugin")
}

kotlin {
jvm()

sourceSets {
commonMain.dependencies {
api(Libs.Coroutines.core)
api(Libs.Serialization.json)
implementation(Libs.Rpc.core)
implementation(Libs.Rpc.serializationJson)
implementation(Libs.datetime)
}
}
}

[Dragos Rachieru]

My project also contains a lot of modules, some depend on compose and dagger

[Dragos Rachieru]

I'm not sure if this might be an issue with KSP, which is used for dagger

[Alexander Sysoev]

I will take a look at the project and see what I can find

[Alexander Sysoev]

Hi @Dragos Rachieru!
In your backend:server module you applied rpc plugin without serialization:

plugins {
    kotlin("jvm")
    id("org.jetbrains.kotlinx.rpc.plugin")
    id("io.ktor.plugin")
}

As I don't see any service defenitions, I suspect you intended to apply org.jetbrains.kotlinx.rpc.platform instead to use bom versions, or it is there just by a accident.
Adding serialization plugin or removing rpc plugin will solve your problem

And I'll take a note for more user friendly experience in similar scenarios

[Dragos Rachieru]

I do not need bom, since I manually specify the library version. What I use in that module is an implementation of an RPC

[Dragos Rachieru]

https://github.com/dragossusi/ktcnc/blob/develop/backend/server/src/main/kotlin/ro/dragossusi/ktcnc/server/service/FileSystemServiceImpl.kt

[Dragos Rachieru]

do I still need to apply the rpc plugin?

[Alexander Sysoev]

Yes, and it does not require an rpc plugin, only service declaration does: interface FileSystemService : RPC

[Dragos Rachieru]

I want to keep all the Serializable classes and RPC interfaces in backend:rpc and i'm keeping all the implementations for these `RPC`s in backend:server

[Dragos Rachieru]

quite strange that ./gradlew build :backend:rpc failed

[Alexander Sysoev]

It failed with the same message?

[Dragos Rachieru]

something similar, related to IR

[Alexander Sysoev]

Hm, I only get

Execution failed for task ':backend:rpc:shadowJar'.
> Error while evaluating property 'mainClassName' of task ':backend:rpc:shadowJar'.
   > Cannot query the value of extension 'application' property 'mainClass' because it has no value available.

trying to run ./gradlew :backend:rpc:build

[Alexander Sysoev]

I'm on the develop branch currently

[Dragos Rachieru]

I am not currently at my PC so I cannot test this right now, I remember running the build task using Intellij, not gradlew

[Dragos Rachieru]

I can try again tonight, I have also upgraded to krpc 0.3.0 using Github directly to see if the same error is shown in Github actions

[Alexander Sysoev]

no problem, please let me know if something still not working when you'll be able to run it

[Alexander Sysoev]

btw, 0.3.0 contains breaking changes in package names, so Ci will probably fail with compilation errors

[Dragos Rachieru]

I tried it yesterday with serialization added to backend:server and the build command succeeded

[Dragos Rachieru]

thanks a lot!