set.java.destinationDirectory.set(new File(project.buildDir, 'classes/java/custom'))
        set.output.resourcesDir == new File(project.buildDir, 'resources/custom')
        set.output.generatedSourcesDirs.files == toLinkedSet(new File(project.buildDir, 'generated/sources/annotationProcessor/java/custom'))

        def processResources = project.tasks['processCustomResources']

            def t = tasks.create("show", SomeTask)
            t.outputDir = layout.buildDirectory.dir(providers.provider { childDirName })
            println "output dir before: " + t.outputDir.getOrNull()
            buildDir = "output/some-dir"
            childDirName = "other-child"
"""

        when:
        run("show")

        then:
        outputContains("output dir before: " + testDirectory.file("build/child"))

        // TODO: synchronization
        File buildDir = buildDefinition.getBuildRootDir();
        if (buildDir == null) {
            throw new IllegalArgumentException("Included build must have a root directory defined");
        }
        IncludedBuildState includedBuild = includedBuildsByRootDir.get(buildDir);
        if (includedBuild == null) {
            if (rootBuild == null) {

    }

    def cannotCreateAnEmptyTar() {
        given:
        buildFile << """
            task tar(type: Tar) {
                from 'test'
                destinationDirectory = buildDir
                archiveFileName = 'test.tar'
            }
            """
        when:
        run "tar"

        then:
        file('build/test.tar').assertDoesNotExist()
    }

                archiveFile.set(project.file("\${buildDir}/foo.zip"))
            }
            task jarTask(type: Jar) {
                from(zipTask)
                archiveFile.set(project.file("\${buildDir}/foo.jar"))
            }
            taskWithInputs {
                sources.from(jarTask)
                outputFile = project.file("\${buildDir}/output.txt")
            }
        """

                attribute(Bundling.BUNDLING_ATTRIBUTE, objects.named(Bundling, Bundling.EXTERNAL))
            }
        }
    }


    artifacts {
        buildDir.mkdirs()
        file("\$buildDir/test.jar").text = "toto"
        runtimeOnly file("\$buildDir/test.jar")
    }
}

dependencies {
    api project(':child')

    artifactTypes.getByName("jar") {

    def "detects when a task removes the build directory #buildDir"() {
        buildFile << """
            apply plugin: 'base'

            project.buildDir = file("${buildDir}")

            task myClean(type: Delete) {
                delete buildDir
            }

            task producer {
                def outputFile = new File(buildDir, "some/file/in/buildDir/output.txt")
                outputs.file(outputFile)

                ${invocation} { println(it.buildDir) }
            }
        """

        when:
        isolatedProjectsFails(":a:help", ":b:help")

        then:
        fixture.assertStateStoredAndDiscarded {
            projectsConfigured(":", ":a", ":b")
            problem("Build file 'a/build.gradle': line 3: Project ':a' cannot access 'Project.buildDir' functionality on $message", accessedProjects)
        }

        createBuildScripts("""
            def customTask = tasks.register("myTask") {
                def buildDir = buildDir
                outputs.file("\${buildDir}/output.txt")
                def outputFile = file("\${buildDir}/output.txt")
                doLast {
                    outputFile << 'custom task'
                }
            }
            publications {

            createFile2.inputFile = layout.projectDirectory.file("file2-source.txt")
            createFile2.outputFile = layout.buildDirectory.file("file2.txt")

            buildDir = "output"
"""
        file("file1-source.txt").text = "file1"
        file("file2-source.txt").text = "file2"

        when:
        run("merge")

        then: