Android N Java 8 features (Jack compiler) and Kotlin interop

Question

Update 3. KOTLIN IS NOW OFFICIALLY SUPPORTED FOR ANDROID DEVELOPMENT. BY GOOGLE. YAAAAAAAAS!

Update 2: It looks like JetBrains is r

Answer 1

As said in the blog post (Kotlin's Android Roadmap) that appeared today:

Right now there are some issues that prevent Jack from handling Kotlin-generated bytecode correctly (196084 and 203531), but we plan to work together with the Google team to either resolve the issues or provide workarounds on our side. Once this is done, we’ll be able to translate only changed class files using Jill during incremental compilation, as opposed to translating all class files every time (which is the only possible behavior in the old Android tooling).

So Kotlin will eventually support Jack & Jill and get benefits from it.