Coroutines Dependency in Kotlin Gradle Plugin

Question

I’m building a Gradle Plugin with Kotlin, in one of the features I’m using Ktor and Coroutines. The plugin must to be included as classpath in third part projects.

Problem comes when I’m trying to use the Plugin in another project, I'm getting:

Caused by: java.lang.NoClassDefFoundError: kotlin/coroutines/Continuation on the consumer project.

I tried to isolate the Coroutines dependencies and apply transitive dependencies for Ktor but no success.

I have seen too different solutions(https://github.com/Kotlin/kotlinx.coroutines/issues/430) like applying ShadowJar to build a FatJar but maybe I’m missing something in the configuration. Once I apply the Shadow Plugin the jar is about 62Mb, even applying minimize size of the jar is 12MB.

The basic conf(based on the samples of Kotlin-DSL) of the plugin would be:

    plugins {
        `kotlin-dsl`
        `maven-publish`
        kotlin("jvm") version "1.3.10"
        id("com.github.johnrengelman.shadow") version "4.0.3"
    }

    gradlePlugin {
       plugins {
          register("greet-plugin") {
             id = "greet"
             implementationClass = "GreetPlugin"
          }
       }

      dependencies {
         api("io.ktor:ktor-client-okhttp:1.0.1")
      }
    }

    val sourcesJar by tasks.registering(Jar::class) {
       classifier = "sources"
       from(sourceSets.main.get().allSource)
    }

    val shadowJar: ShadowJar by tasks
        shadowJar.apply {
           baseName = "test"
           classifier = ""
           minimize()
    }

The complete example is here: https://github.com/cdsap/testPluginCoroutinesProblem

A more detailed error

    java.lang.NoClassDefFoundError: kotlin/coroutines/Continuation
            at io.ktor.client.engine.okhttp.OkHttp.create(OkHttp.kt:8)
            at io.ktor.client.HttpClientKt.HttpClient(HttpClient.kt:36)
            at io.ktor.client.HttpClientKt.HttpClient$default(HttpClient.kt:33)
            at GreetPlugin.apply(GreetPlugin.kt:26)
            at GreetPlugin.apply(GreetPlugin.kt:12)

I expect the plugin will build properly the coroutines dependency within Ktor and don't have big jar as dependency.

Coroutines Dependency in Kotlin Gradle Plugin

0 Answers