Urlclassloader and proxied annotations in gradle

code_bar_build.gradle

apply plugin: 'java'

dependencies {
    compile project (':foo')
}

code_bar_src_main_java_Bar.java

@Foo
public class Bar {

}

code_foo_build.gradle

apply plugin: 'java'

code_foo_src_main_java_Foo.java

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Foo {

}

core_settings.gradle

include 'foo'
include 'bar'

failing_build.gradle

buildscript {
    repositories {
        flatDir dirs: ['../code/foo/build/libs']
    }
    dependencies {
        classpath (':foo:')
    }
}

import java.lang.annotation.Annotation

ClassLoader cl = new URLClassLoader(['../code/foo/build/libs/foo.jar', '../code/bar/build/libs/bar.jar'].collect {file(it).toURI().toURL()}.toArray (new URL[0]));
Class<?> barClass = cl.loadClass("Bar");

Annotation[] annotations = barClass.getAnnotations();
annotations.each {Annotation annotation->
    logger.lifecycle ("Annotations contains: "+annotation.annotationType());
}

def annotation = barClass.getAnnotation(Foo) //FAILS

assert annotation

working_build.gradle

import java.lang.annotation.Annotation

ClassLoader cl = new URLClassLoader(['../code/foo/build/libs/foo.jar', '../code/bar/build/libs/bar.jar'].collect {file(it).toURI().toURL()}.toArray (new URL[0]));
Class<?> barClass = cl.loadClass("Bar");

Annotation[] annotations = barClass.getAnnotations();
annotations.each {Annotation annotation->
    logger.lifecycle ("Annotations contains: "+annotation.annotationType());
}

def annotation = barClass.getAnnotation(cl.loadClass("Foo")) //WORKS

assert annotation