Unlike in Qt 5.2.1, with Qt 5.3.0 I get random hang up of QMenu::exec
Nothing is responding and the application has to be hard-quitted.
Under the debugger, [NSApp run] is called and hanging happens a bit below.
By running and pausing the debugger, I can see that some event activity is still happening, as breaking does not always happen at the same point. But the whole Qt UI is freezed.