Crash in QQmlObjectCreator::setPropertyBinding()

import QtQuick 2.5
import QtQuick.Window 2.2
import QtQuick.Dialogs 1.2

import MyControls 1.0
import Qt.labs.controls 1.0 as LabCtrl

Window {
    title: qsTr("Hello World")
    width: 640
    height: 480
    visible: true

    ButtonGroup {
        id: grp
    }

    Row {
        id: row

        RadioButton {
            text: "hello"
            //ButtonGroup.group: grp // !!! This will crash !!!
            LabCtrl.ButtonGroup.group: grp // !!! This works !!!
        }

        RadioButton {
            text: "bye"
            //ButtonGroup.group: grp // !!! This will crash !!!
            LabCtrl.ButtonGroup.group: grp // !!! This works !!!
        }
    }

    Flickable {
       anchors.top: row.bottom
       width: 200
       height: 100
       contentWidth: 200
       contentHeight: 200
       clip: true

       //LabCtrl.ScrollBar.vertical: ScrollBar{} // !!! This will crash !!!
       //LabCtrl.ScrollBar.vertical: LabCtrl.ScrollBar{} // !!! This will crash !!!

       Rectangle {
         width: 200
         height: 200
         gradient: Gradient {
           GradientStop {position: 0.0; color: "red"}
           GradientStop {position: 0.5; color: "green"}
           GradientStop {position: 1.0; color: "blue"}
         }
       }
    }
}