$ touch target/out/jvm/scala-2.12.17/compile-clean/backend/cant-touch-this

> Test/compile
$ exists target/out/jvm/scala-2.12.17/compile-clean/backend/A.class
$ exists target/out/jvm/scala-2.12.17/compile-clean/backend/X.class
$ exists target/out/jvm/scala-2.12.17/compile-clean/test-backend/B.class

> Test/clean
$ exists target/out/jvm/scala-2.12.17/compile-clean/backend/cant-touch-this
$ exists target/out/jvm/scala-2.12.17/compile-clean/backend/A.class
$ exists target/out/jvm/scala-2.12.17/compile-clean/backend/X.class
$ absent target/out/jvm/scala-2.12.17/compile-clean/test-backend/B.class

> Compile/clean
$ exists target/out/jvm/scala-2.12.17/compile-clean/backend/cant-touch-this
$ absent target/out/jvm/scala-2.12.17/compile-clean/backend/A.class
$ exists target/out/jvm/scala-2.12.17/compile-clean/backend/X.class
