4.10.1 & 4.10.2: Cannot publish artifact 'compileScala.mapping' (PATH) as it does not exist.

[drujd]

project(':scala-for-tests-only') {
    apply plugin: 'java-library'
    apply plugin: 'scala'
    apply plugin: 'maven'

    repositories {
        mavenCentral()
    }

    //scala joint compilation for tests
    sourceSets.test.java.srcDirs.each { sourceSets.test.scala.srcDir it }
    sourceSets.test.java.srcDirs = []

    dependencies {
        compile 'org.scala-lang:scala-library:2.12.6'
    }
}

This project (which contains only Java main classes, but utilises Scala for joint compilation of Java and Scala test classes) fails on :scala-for-tests-only:install with

Execution failed for task ':test-classes-only:install'.
> Could not publish configuration 'archives'
   > Cannot publish artifact 'compileScala.mapping' (PATH\test-classes-only\build\tmp\scala\compilerAnalysis\compileScala.mapping) as it does not exist.

This happens only on 4.10.1 and 4.10.2. 4.10 and older versions work.

[big-guy]

Yep, I've confirmed this.

As a workaround, you can create a src/main/scala/ScalaForTestsWorkaround.scala with something like class ScalaForTestsWorkaround in it.

Is test-classes-only used for sharing test fixtures/base classes with other projects or does it build other things in src/main?

[drujd]

The problem occurs in both cases. If there are some non-test java (but not scala) classes, the easy fix is to also add

sourceSets.main.java.srcDirs.each { sourceSets.main.scala.srcDir it }
sourceSets.main.java.srcDirs = []

so the joint compiler is used for the java classes. If there are only test classes in the project, then you have to use the ugly workaround. :/

[big-guy]

If there are only test classes, you could also put everything in "main" if you are sharing those classes with other projects. This is what we do in gradle/gradle for our testing only infrastructure projects.

[brosander]

Seeing this as well in modules that have all java source + scalatests

[drujd]

@brosander That can be fixed by

sourceSets.main.java.srcDirs.each { sourceSets.main.scala.srcDir it }
sourceSets.main.java.srcDirs = []

[ymwang1984]

Seeing this as well in some of our production Scala projects at LinkedIn

[drujd]

@big-guy Moving tests to main is a pretty ugly workaround.

[zatekusen]

We seeing this error appeared randomly even in normal module as well. Haven't investigated further but it does look like that it happens when we just rerun the same build and some tasks are cached.

[drujd]

Yup. With 4.10 this works well, but there are other bugs...

[big-guy]

This will be released in 4.10.3 (hopefully today)

[drujd]

Is the fix present also in 5.0?

[big-guy]

Yes