QML MediaPlayer crashed when try to switch a media source

import QtQuick 2.3
import QtQuick.Window 2.2
import QtMultimedia 5.0

Window {
    visible: true
    MediaPlayer {
        id: mp
        autoPlay: true
    }
    Timer {
        id: t
        interval: 100
        running: true
        repeat: true
        property bool toggled;
        onTriggered: {
            toggled = !toggled;
            mp.source = toggled ? "" : "qrc:/song.mp3"
        }
    }
}