Better build instructions or release a pre-built jar

[stkgo]

I am trying to build the package following the build instructions from the README and am encountering the following error

FAILURE: Build failed with an exception.

* What went wrong:
Could not initialize class org.codehaus.groovy.runtime.InvokerHelper
> Exception java.lang.NoClassDefFoundError: Could not initialize class org.codehaus.groovy.reflection.ReflectionCache [in thread "Daemon worker"]

I have Groovy and OpenJDK installed, but I am unsure how to proceed since the build instructions do not specify any versions or additional required dependencies.