Extension methods not recognized by Gradle

If you annotate a groovy class with @TypeChecked or @CompileStatic and that the code uses an extension module, then compilation fails as if the type checker doesn't find the extension classes.

Using

compileTestGroovy.groovyOptions.useAnt = true

fixes the problem.
To reproduce, first step will build and install an extension module into local maven repo.

$ git clone  https://github.com/swilliams-vmw/gemfire-groovy-extensions.git
$ cd gemfire-groovy-extensions
$ ./gradlew install

Second, download this test project: http://dl.dropbox.com/u/20288797/dive...

$ cd test
$ ./gradlew clean test

passes. Now open build.gradle, remove the useAnt=true option and the project compilation fails.

Investigation shows that the type checker should try to load the extension modules from the source unit classpath instead of using the ones from the MetaClassRegistry.