}
                if (property.isDeclaredAsHavingUnmanagedType()) {
                    throw new UnmanagedPropertyMissingSetterException(property.getName());
                }
            }
        } else if (!shouldHaveANodeInitializer(property, propertySchema) && !property.isWritable() && !isNamePropertyOfANamedType(property)) {

                * property(a, literal(33)) -> ShadowedProperty(underlayProperty=property(a, literal(3)), overlayProperty=property(a, literal(33)))
                    - literal(33) -> FromOverlay(documentNode=property(a, literal(33)))
                * property(b, literal(6)) -> FromOverlay(documentNode=property(b, literal(6)))
                    - literal(6) -> FromOverlay(documentNode=property(b, literal(6)))

        def owner = Stub(ModelObject)
        _ * owner.taskThatOwnsThisObject >> task
        def property = TestUtil.objectFactory().property(String)
        property.attachOwner(owner, Describables.of("<prop>"))
        property.attachProducer(owner)
        property.set("12")
        return property
    }

    Property<String> propertyWithCompletedProducer() {
        def task = Mock(Task)
        def state = Mock(TaskState)

    }

    public AbstractBuildOption(String property, V... commandLineOptionConfiguration) {
        this(property, null, commandLineOptionConfiguration != null ? Arrays.asList(commandLineOptionConfiguration) : Collections.<V>emptyList());
    }

    private AbstractBuildOption(String property, String deprecatedProperty, List<V> commandLineOptionConfigurations) {
        this.property = property;
        this.deprecatedProperty = deprecatedProperty;

tasks.register("show") {
    def property = objects.property(String)

    // Set a convention
    property.convention("convention 1")

    println("value = " + property.get())

    // Can replace the convention
    property.convention("convention 2")
    println("value = " + property.get())

    property.set("explicit value")

    // Once a value is set, the convention is ignored
    property.convention("ignored convention")

tasks.register("show") {
    val property = objects.property(String::class)

    // Set a convention
    property.convention("convention 1")

    println("value = " + property.get())

    // Can replace the convention
    property.convention("convention 2")
    println("value = " + property.get())

    property.set("explicit value")

    // Once a value is set, the convention is ignored
    property.convention("ignored convention")

            tasks.create("thing", MyTask) {
                println("property = \$count")
                count = 12
            }
        """

        when:
        succeeds("thing")

        then:
        outputContains("property = task ':thing' property 'count'")
        outputContains("count = 12")
    }

    def "reports failure to query managed Property<T> with no value"() {
        given:
        buildFile << """

        "System.properties['some.property']"                   | _
        "System.getProperties().get('some.property')"          | _
        "getProperties().get('some.property')"                 | _
        "System.getProperty('some.property')"                  | _
        "getProperty('some.property')"                         | _
        "System.getProperty('some.property', 'default.value')" | _
        "getProperty('some.property', 'default.value')"        | _

        "System.getProperties().get(\"some.property\")"            | _
        "System.getProperty(\"some.property\")"                    | _
        "System.getProperty(\"some.property\", \"default.value\")" | _
        "System.setProperty(\"some.property\", \"new.value\")"     | _
        "System.clearProperty(\"some.property\")"                  | _
    }

    def "setProperties is instrumented in Java"() {

        when:
        configurationCacheRun("-Dsome.property.1=1", "-Dsome.property.2=2", "print")

        then:
        configurationCache.assertStateStored()
        outputContains("Configuration: some.property.1 = 0")
        outputContains("Configuration: some.property.2 = 2")

        when:
        configurationCacheRun("-Dsome.property.1=-1", "-Dsome.property.2=2", "print")

        then: