Cannot build Grails app in Eclipse with Java 1.8

Question

I\'ve inherited a Grails project and am trying to build it in eclipse with Java 1.8. I can successfully build a war file with Java 1.7 but when I switch to 1.8 and rebuild I get

Answer 1

Because Grails v2.1.2 does not support java8. Java8 support is available from 2.4.x onwards.

Ref# GRAILS-11063