If you're encountering a StackOverflowError during compilation of
drools-compiler,
it's not uncommon, most of us seen it already.
There's an easy fix: see the /README.txt file on how to deal with it in
Eclipse/IntelliJ.
We're still looking for the true cause, in case you want to help out,
here's the issue:
https://issues.jboss.org/browse/JBRULES-2829
--
With kind regards,
Geoffrey De Smet