QOpenGLWidget core profile not working on Mac

The hellogl2 example that ships with Qt does not work when the format is set to use CoreProfile (command line option --coreprofile). In this case the example renders a black screen. Without the --coreprofile option it works fine, but this is nearly useless for modern OpenGL development.

I discovered this while trying to figure out why do I get a black screen in my own use of QOpenGLWidget, so the bug is probably not in the example.