on kotlin 1.8.0, in a project with mixed kotlin and java code (converting java project to kotlin), any idea why i have this error : Unrecognized option: -Xuse-k2

maybe you use the wrong KotlinCompile? This works for me in my build.gradle.kts:

tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
    kotlinOptions.useK2 = true
}

there is another

KotlinCompile

class in package

org.jetbrains.kotlin.gradle.dsl

, but that one doesn't work.