Closures in a derived class can't access package private fields of the base class in the same package.

Java:
public class A

Groovy
class B extends A { doGreet =

}
new B().doGreet().call()

Both A and B are in the same package.
Code in the closure will throw a MissingPropertyException, as greeting is not accessible but it should be.
Changing this to either protected or public is a workaround.

Attached test cases perform various visibilty tests.