How to define classpath of groovyOptions.configurationScript?


recently I discovered the configuration script option for the groovyCompile task. I use it like this:

compileGroovy {
        groovyOptions.configurationScript = file("/config.groovy")

How do I set the classpath of the config.groovy script? I want to register a custom ast transform and the config scipt does not find it.

I have already tried to set the buildscript classpath dependencies:

buildscript {
    dependencies {
        classpath files("path/to/mylib.jar");

Unfortunately, that does not work. What is the suggested way to set the classpath?

Update [10/6/2015] : still does not seem to work with Gradle 2.7. Any ideas? Is it a bug?