val Project.gradleInstallPath: Provider<String>
    get() = gradleProperty(GRADLE_INSTALL_PATH).orElse(
        provider<String> {
            throw RuntimeException("You can't install without setting the $GRADLE_INSTALL_PATH property.")
        }
    )


val Project.rerunAllTests: Provider<Boolean>
    get() = gradleProperty(RERUN_ALL_TESTS).map { true }.orElse(false)

        jvm.jre == software.file('jdk/jre')
        jvm.embeddedJre == software.file("jdk/jre")
        jvm.standaloneJre == null
        jvm.jre == jvm.embeddedJre
    }

    def "locates JDK install for a typical Java 9 JDK installation"() {
        given:
        def java9ImplementationVersion = "9.0.3"
        def software = tmpDir.createDir('software')
        software.create {
            jdk {

}

tasks.register("installBuildBuilder", GradleBuild) {
    dir = buildBuilder.outputDirectory
    tasks = ['install']
    dependsOn buildBuilder
}

tasks.withType(BuildBuilderGenerator).configureEach {
    buildBuilderInstall = new File(tasks.buildBuilder.outputDirectory, "build/install/build-builder")
    dependsOn installBuildBuilder
}

1. Run tests.
- Run `./gradlew :<subproject>:quickTest` where `<subproject>` is the name of the subproject you've changed. 
- For example: `./gradlew :launcher:quickTest`.
2. Install Gradle locally and try out a change in behavior manually. 
- Install: `./gradlew install -Pgradle_installPath=/any/path`
- Use: `/any/path/bin/gradle taskName`.