I tried the following:
$ git clone https://github.com/ReactiveX/RxKotlin.git
$ cd RxKotlin/
$ gradle build
It fails with:
...FAILURE: Build failed with an exception.
Where: Build file '/home/myuser/RxKotlin/build.gradle' line: 13
What went wrong: A problem occurred evaluating root project 'rxkotlin'.
org/gradle/api/internal/project/AbstractProject