}
    }

    private
    fun runner() = GradleRunner.create()
        .withProjectDir(projectRoot)
        .withPluginClasspath()
        .forwardOutput()
        .withArguments(":distribution:mergeInstrumentedSuperTypes", ":distribution:mergeUpgradedProperties", "--stacktrace")

    private
    fun assertSucceeds() {

        when:
        def runner = createRunner()
            .withArguments(originalArguments)
            .withJvmArguments(originalJvmArguments)
            .withPluginClasspath(originalClasspath) as DefaultGradleRunner

        then:
        runner.arguments == originalArguments
        runner.jvmArguments == originalJvmArguments
        runner.pluginClasspath == originalClasspath

                            .withTestKitDir(new File("${TextUtil.normaliseFileSeparators(executer.gradleUserHomeDir.absolutePath)}"))
                            .withPluginClasspath()
                            .withProjectDir(rootDir)
                            .withArguments("help")
                        def result = runner.${testKitSpec.succeeds ? "build" : "buildAndFail"}()

                        plugins { id 'my-plugin' }
                    '''

                    def runner = GradleRunner.create()
                    runner.forwardOutput()
                    runner.withPluginClasspath()
                    runner.withArguments("help")
                    runner.withProjectDir(projectDir)
                    runner.withDebug(true)
                    def result = runner.build()
                }