def srcDir = tmpDir.file("source")

    def "mixes GroovyObject into JavaPluginConvention"() {
        given:
        def className = "org.gradle.api.plugins.JavaPluginConvention"

        def original = compileJavaToDir(className, """
            package org.gradle.api.plugins;
            class JavaPluginConvention {
                String _prop;
                String getProp() { return _prop; }