Gradle building empty JAR file

Hello, I am having an issue trying to use Gradle: Whenever I try to build my plugin, I get an empty JAR file. I’ve Gradle before, but never have had this issue. The same problem happens on other computers, so it is not a local issue. The code can be found here. Does anyone have any ideas how to fix this?

You should put your source files in src/main/java or change the gradle sourceSet to be src

It seems to work now, thanks!