A DESCRIPTION OF THE PROBLEM :
Unable to call default method from interface in an other module from named module.

Using Lookup.findSpecial it is possible to get a MethodHandle for the default method of an interface.
This only works if the code is in an unnamed module.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Try to find a MethodHandle for a default method of an interface in an other module from a named module.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
A MethodHandle for the default method is returned.
ACTUAL -
An exception is thrown.

---------- BEGIN SOURCE ----------
package bug;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.invoke.MethodHandles.Lookup;
import java.lang.reflect.Method;
import java.util.Comparator;

public class ModuleFindDefault {
	private static final Lookup LOOKUP = MethodHandles.lookup();
	
	public static void main(String[] args) throws Throwable {
		Method method = Comparator.class.getMethod("reversed");
		Comparator<Object> cmp = new TestInterf();

		MethodHandle mhFind = findSpecial(method);
		Object findRev = mhFind.invoke(cmp);
		System.out.println(findRev);
	}
	
	static MethodHandle findSpecial(Method m) throws ReflectiveOperationException {
		return LOOKUP.findSpecial(m.getDeclaringClass(), m.getName(), 
				MethodType.methodType(m.getReturnType(), m.getParameterTypes()), 
				m.getDeclaringClass());
	}
	
	static class TestInterf implements Comparator<Object> {
		
		public int compare(Object o1, Object o2) {
			return 0;
		}
		
		@Override
		public Comparator<Object> reversed() {
			System.out.println("ModuleFindDefault.TestInterf.reversed()");
			return this;
		}
		
	}
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Get somehow a private lookup in an unnamed module:

Create a ClassLoader, define a class, get the Lookup from this class?

FREQUENCY : always