Assert from qpaintengineex_opengl2.cpp (in function: bool QGL2PaintEngineEx::begin(QPaintDevice *pdev)) on checking the capabilities/features of opengl driver (this section of code: #if !defined(QT_OPENGL_ES_2)
bool success = qt_resolve_version_2_0_functions(d->ctx)
&& qt_resolve_buffer_extensions(d->ctx);
Q_ASSERT(success); <-this is the assert
Q_UNUSED(success);
#endif
when using the QGLWidget() as the background in a QGraphicsView widget. Intel driver claims it is OpenGL 2.0 compatible, Qt documentation claims the same. Not sure who's right.

Forcing the paint engine to OpenGL 1.1 causes unbearable artifacts in image.