Test case: tst_qquickwidget

When I run this test case on my target board using Wayland, an error occurs. Although the red color is correctly displayed on the monitor, the read-back value is incorrect. Please help me find a solution. Here is my log:

FAIL!  : tst_qquickwidget::readback() Compared values are not the same
   Actual   (pix)            : 4278190080
   Expected (qRgb(255, 0, 0)): 4294901760
   Loc: [tst_qquickwidget.cpp(266)]

Here is the content of my rectangle.qml file::

import QtQuick 2.0
Rectangle