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

        when:
        executer.withArguments(ENABLE_CLI)
        def model4 = runBuildAction(new FetchCustomModelForEachProjectInParallel())

== Step 1. Understanding Incremental Builds
It's important to know that Gradle optimizes your build in a variety of ways.
One such optimization is called _incremental builds_.

An _incremental build_ is a build that avoids running tasks whose inputs did not change since the previous build, making the execution of such tasks unnecessary.

* The build's output;
* The build's logging (i.e. console output);
* The set of tasks executed by the build and their results (e.g. FAILED, UP-TO-DATE etc.).

        when:
        run 'otherBuild'

        then:
        result.assertTaskExecuted(":other:buildSrc:jar")
    }

    def "buildSrc can have nested build"() {
        given:
        file('buildSrc/src/main/java/Thing.java') << "class Thing { }"
        file('buildSrc/build.gradle') << """
            task otherBuild(type:GradleBuild) {
                dir = '../other'
                tasks = ['build']

    }

    def "build uses jar from buildSrc"() {
        writeBuildSrcPlugin("buildSrc", "MyPlugin")
        buildFile << """
            apply plugin: MyPlugin
            // nuke buildSrc classes so we can't use them
            project.delete(file("buildSrc/build/classes"))
        """
        when:
        succeeds("myTaskMyPlugin")
        then:

        expect:
        executer.usingProjectDirectory(file("buildSrc"))
        fails("tasks")

        file("buildSrc").assertIsEmptyDir()
        assertNoProjectCaches(executer.gradleUserHomeDir)
    }

    def "treats empty buildSrc inside a build as undefined build"() {
        given:
        settingsFile.touch()
        file("buildSrc").createDir()

        expect:

        }
    }

    static class BuildSrc implements BuildWithSystemPropertyDefined {

        @Override
        void setup(AbstractIntegrationSpec spec, String propertyKey) {
            spec.testDirectory.file("buildSrc/gradle.properties") << "systemProp.$propertyKey=${propertyValue()}"
            spec.testDirectory.file("buildSrc/build.gradle").touch()
        }

        @Override

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

        and:
        fixture.assertStateUpdated {
            fileChanged("build.gradle")
            projectConfigured(":buildSrc")
            modelsCreated(":")
            modelsReused(":a", ":b", ":buildSrc")
        }
        outputContains("creating model for root project 'root'")

        when:
        executer.withArguments(ENABLE_CLI)

    }

    def "invalidates cache upon change to #inputName used by buildSrc"() {

        assumeFalse(
            'property from gradle.properties is not available to buildSrc',
            inputName == 'gradle.properties'
        )

        given:
        def configurationCache = newConfigurationCacheFixture()
        file("buildSrc/build.gradle.kts").text = """

        and:
        fixture.assertStateUpdatedWithProblems {
            fileChanged("build.gradle")
            projectConfigured(":buildSrc")
            modelsCreated(":a", ":b")
            modelsQueriedAndNotPresent(":")
            modelsReused(":c", ":buildSrc")
            problem("Build file 'build.gradle': line 10: Project ':' cannot access 'Project.afterEvaluate' functionality on another project ':a'")