documentation non up to date at http://gradle.org/docs/current/dsl/org.gradle.api.tasks.compile.Compile.html
File destinationDir
The directory to generate the .class files into.
Default with java plugin:
sourceSet.classesDir
This is the old value, which is now wrong. The correct statement should be:
File destinationDir
The directory to generate the .class files into.
Default with java plugin:
sourceSet.output.classesDir
Please insert the “output” which is missing