sourceSets with gradle kotlin DSL in grade 4.10rc

Question

I am using the following code:

java.sourceSets["main"].java {
    srcDir("src/main/extraSource")
}

works perfectly in gradle 4.9, but in 4.10 rc1 gives the following error:

  Line 5: java.sourceSets["main"].java {
               ^ Unresolved reference. None of the following candidates is applicable because of receiver type mismatch: 
                   public val Project.sourceSets: SourceSetContainer defined in org.gradle.kotlin.dsl

Any ideas? Has there been a change to what is needed? Many other answers (eg. this one and every suggested answer to this question) will also need updates if this has changed

Answer 1

This is an expected breaking change and is listed at https://docs.gradle.org/4.10-rc-2/release-notes.html#changes-to-the-gradle-kotlin-dsl

But unfortunately it's missing in the Kotlin DSL release notes, it'll be fixed for 4.10 GA.

In a nutshell, java.sourceSets is now sourceSets. For your example the fixed script is:

sourceSets["main"].java {
    srcDir("src/main/extraSource")
}

It’s a change in gradle/gradle, see https://github.com/gradle/gradle/pull/5867 for some background.