Stopping debugged Qt Quick UI project freezes Creator for too long

1. Open project qtdeclarative\examples\quick\demos\samegame\samegame.qmlproject from Qt5's repository.
2. Configure the project to use Qt 5.4.2.
3. Set a breakpoint at the first line of function startNewGame(gc, mode, map).
4. Run the project in debugger.
5. In the app, click "1 Player".
   The breakpoint is being hit.
6. Click the "Stop Debugger" icon.
   Creator will free for about 30 seconds before the debugger finally quits.

The debugger should stop more quickly and Creator should not freeze.