ScrollBar QML crash

[EStudley]

Does anyone know why the following code crashes when the ListView anchors.margins is uncommented and the list's contentHeight grows larger than it's height?

ApplicationWindow {
    width: 200
    height: 480
    visible: true
    title: qsTr("Hello World")
    color: "black"

    ListView {
        id: listView
        z: -1
        anchors.fill: parent
//        anchors.margins: 10
        spacing: 10
        model: 1

        ScrollBar.vertical: ScrollBar {
            id: scrollBar
            visible: parent.contentHeight > parent.height
            padding: 20
        }

        delegate: Rectangle {
            width: parent.width - (scrollBar.visible ? scrollBar.width : 0)
            height: width

            MouseArea {
                anchors { fill: parent }

                onClicked: listView.model++
            }
        }
    }
}

Commenting out the anchors.margins causes it not to crash. Changing scrollBar.padding to 10 causes it not to crash.

I can't figure out what's going on with ScrollBar here.