allprojects {
    task("hello") {
        doLast {
            println("I'm ${this.project.name}")
        }
    }
}
subprojects {
    tasks.getByName("hello") {
        doLast { println("- I depend on water") }
        afterEvaluate {
            if (extra["arctic"] as Boolean) {
                doLast {
                    println("- I love to spend time in the arctic waters.")
                }
            }
        }
    }
}
