QSGThreadedRenderLoop deadlock

#include <QtQuick>

class MyWindow : public QQuickWindow
{
protected:
    void mouseMoveEvent(QMouseEvent *ev)
    {
        static QPoint lastPos = ev->pos();
        if (QPoint(lastPos - ev->pos()).manhattanLength() > 50) {
            QQuickWindow* child = new QQuickWindow;
            child->setTransientParent(this);
            child->setFlags(Qt::Popup);
            child->resize(100, 100);
            child->show();
            QTimer::singleShot(100, child, SLOT(close()));
            QTimer::singleShot(1000, child, SLOT(deleteLater()));
            static int i = 0;
            qDebug() << ++i;
        }
    }
};

int main(int argc, char *argv[])
{
    QGuiApplication a(argc, argv);
    MyWindow window;
    window.resize(320, 240);
    window.show();
    return a.exec();
}