Idea and scala plugins broken together in subproject

Bugs
1

Gradle Version: 2.14(.1)
Operating System: Arch Linux
Is this a regression? If yes, which version of Gradle do you know it last worked for? Not regression as far as I am aware.

https://github.com/robotbrain/skychat In forge subproject. the forge plugin applies idea automatically.

2

The issue appears to be resolved by applying the idea plugin to the root project.