""")
        withBuildScriptIn("buildSrc/c", """
            plugins { java }
            $repositoriesBlock
        """)

        return [
            withMainSourceSetJavaIn("buildSrc"),
            withMainSourceSetJavaKotlinIn("buildSrc/a"),
            withMainSourceSetJavaKotlinIn("buildSrc/b"),
            withMainSourceSetJavaIn("buildSrc/c")
        ] as ProjectSourceRoots[]
    }

    }

    @Requires(IntegTestPreconditions.NotParallelExecutor)
    @LeaksFileHandles
    def "tasks stay cached after buildSrc with custom Kotlin task is rebuilt"() {
        withKotlinBuildSrc()
        file("buildSrc/src/main/kotlin/CustomTask.kt") << customKotlinTask()
        file("input.txt") << "input"
        buildFile << """
            task<CustomTask>("customTask") {
                inputFile = project.file("input.txt")

/**
 * A set of helpers to generate a Groovy plugin with provided code in buildSrc and apply it to the project under test.
 * The trait is intended to be mixed into something that extends {@link org.gradle.integtests.fixtures.AbstractIntegrationSpec}.
 */
trait DynamicGroovyPluginMixin {
    void withPluginCode(String imports, String codeUnderTest, boolean enableIndy) {
        file("buildSrc/src/main/groovy/SomePlugin.groovy") << """

    }

    def setupGradleOpts() {
        useG1GarbageCollectorOnJava8(runner)
    }

    def "buildSrc abi change"() {
        given:
        setupGradleOpts()
        runner.tasksToRun = ['help']
        runner.runs = determineNumberOfRuns(runner.testProject)

        and:
        def changingClassFilePath = "buildSrc/src/main/groovy/ChangingClass.groovy"

The `myproject.java-conventions` plugin is then applied to the `buildSrc` build:
====
include::sample[dir="kotlin",files="buildSrc/build.gradle.kts[tags=plugins]"]
include::sample[dir="groovy",files="buildSrc/build.gradle[tags=plugins]"]
====

It is also applied in the subprojects of the root project:
====

    def "can use task types defined in buildSrc"() {
        given:
        createDirs("buildSrc/ignored")
        file("buildSrc/settings.gradle") << """
            include 'ignored' // include some content
        """
        file("buildSrc/build.gradle") << """
            allprojects { apply plugin: 'java-library' } // include some content
        """
        file("buildSrc/src/main/java/CustomTask.java") << """

        model3[1].message == "It works from project :a"

        fixture.assertStateUpdated {
            fileChanged("build.gradle")
            projectConfigured(":buildSrc")
            modelsCreated(":")
            modelsReused(":a", ":b", ":buildSrc")
        }

        outputContains("Callback before root project 'root'")
        outputDoesNotContain("Callback before project ':a'")

        """

        when:
        executer.withArguments(ENABLE_CLI)
        fetchModelFails()

        then:
        fixture.assertStateStoredAndDiscarded {
            projectConfigured(":buildSrc")
            modelsCreated(":")
            problem("Build file 'build.gradle': line 3: Project ':' cannot access 'Project.plugins' functionality on subprojects via 'allprojects'", 2)
        }

        when:

    def "emits once when not used"() {
        given:
        settingsFile << "includeBuild 'plugin'"
        file("buildSrc/src/main/java/Thing.java") << "class Thing {}"
        createDir("plugin") {
            file("settings.gradle") << ""
            file("build.gradle") << "plugins { id 'java' }"
            file("buildSrc/src/main/java/Thing.java") << "class Thing {}"
            file("src/main/java/Thing.java") << "class Thing {}"
        }

println 'nestedBuild buildSrc quiet'