How to build sources jar with gradle
===

I am working with an open source project that is built with gradle.  I would like to generate a (project)-sources.jar file that I can load into my IDE (IntelliJ IDEA) and debug through the project.  I know how to load the file if I can generate it.

I have looked through the available gradle tasks for the project and there isn't one that generates a sources jar file.

What is the easiest way to generate a sources jar file for this project?

Adding the source into the jar file that contains the compiled class files would be fine as well.