[1.8][Scala]Unable to link scala mod with gradle

Now I'm trying to write minecraft 1.8 mod with scala, but some problem occured while I'm trying to build jar with Gradlew.

·I'm in win10. No problem happend about it.

·I set the gradlew for eclipse, and in eclipse the mod works very well, every object is complied.

·I set the environment correctly, and the command scala and scalac works.

·When I try to build mod with gradlew, all the scala object is missed, and only java class was linked into the jar.

·But I find all the class from scala object in /bin/, and when I put them into jar by hand, the mod works correctly.

I think it is a small linking(or how you call it in java?) problem, and I hope you can repair the problem in the next gradlew version.