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kotlinlang

I've started seeing the following get printed when running gradle tasks from the command line:

```&gt; Task :buildSrc:compileKotlin
'compileJava' task (current target is 11) and 'compileKotlin' task (current target is 1.8) jvm target compatibility should be set to the same Java version.```
My buildSrc `build.gradle.kts` is in :thread: and I believe I'm setting all of the Java and Kotlin targets correctly.

```@file:Suppress("UnstableApiUsage")

import org.jetbrains.kotlin.gradle.tasks.KotlinCompile

plugins {
  `kotlin-dsl`
}

repositories {
  mavenCentral()
  google()
}

tasks.withType&lt;JavaCompile&gt; {
  sourceCompatibility = libs.versions.jdk.get()
  targetCompatibility = libs.versions.jdk.get()
}

kotlin {
  jvmToolchain {
    (this as JavaToolchainSpec).languageVersion.set(JavaLanguageVersion.of(libs.versions.jdk.get()))
  }
}

tasks.withType&lt;KotlinCompile&gt;().configureEach {
  kotlinOptions {
    jvmTarget = libs.versions.jdk.get()

    allWarningsAsErrors = true
  }
}

dependencies {
  implementation(files(libs.javaClass.superclass.protectionDomain.codeSource.location))
  implementation(libs.buildscript.android)
  implementation(libs.buildscript.kotlin)
  implementation(libs.buildscript.detekt)
  implementation(libs.kotlinx.serialization)
  implementation(libs.ejson)
}```

kotlin-dsl forces jvm target to 1.8, so you have to set toolchain in `buildSrc` to 8

Interesting. Is the kotlin-dsl jvm target exposed anywhere so that I can set the toolchain based on that?

related: <https://youtrack.jetbrains.com/issue/KT-48745>

Oh excellent. Now I just need 1.6.0 :clock6:

1.8 is set by Gradle as Gradle itself supports running on JDK 1.8+.

Kotlin-DSL sets jvm target <https://github.com/gradle/gradle/blob/d61adb88e64d55c1eb398287ba30b6960b20031c/subprojects/kotlin-dsl-plugins/src/main/kotlin/org/gradle/kotlin/dsl/plugins/dsl/KotlinDslCompilerPlugins.kt#L47|here>, where current target itself is <https://github.com/gradle/gradle/blob/d61adb88e64d55c1eb398287ba30b6960b20031c/subprojects/kotlin-dsl-plugins/src/main/kotlin/org/gradle/kotlin/dsl/plugins/dsl/KotlinDslPluginOptions.kt#L42|here>.

I'm fine with it being 1.8

I was just trying to make the warning go away (which it seems like Kotlin 1.6.0 will do)

`'compileJava' task (current target is 11) and 'compileKotlin' task (current target is 1.8) jvm target compatibility should be set to the same Java version.` - this warning was introduced in the Kotlin 1.5.30 and does not relate to the linked issue above. Generally best solution would be to set toolchain to 8 java version. Also you could disable this warning at all: <https://kotlinlang.org/docs/gradle.html#check-for-jvm-target-compatibility>

Wouldn't the linked issue apply since I don't have any Java sources?

If not, would the solution be to set the toolchain to `kotlinDslPluginOptions.jvmTarget.get()`? If so, is that something the plugin should do?

You may still have Groovy compiled classes :slightly_smiling_face:

But there was also a bug in 1.5.30 which produce this warning on empty java sources. Should be fixed in 1.6.0

This made the warning go away for me (in `buildSrc/build.gradle.kts`):
```java {
  sourceCompatibility = JavaVersion.VERSION_1_8
  targetCompatibility = JavaVersion.VERSION_1_8
}```
I expect to be able to delete the above code after updating to Kotlin 1.6 (I don’t have any Java code in `buildSrc`).