please test under Mac OS

Travis-CI will fail on macOS when it finally gets to that @YoshiMan ;)

http://doc.qt.io/qt-5/qkeysequence.html#qt_set_sequence_auto_mnemonic
Note: This function is not declared in any of Qt's header files.
To use it in your application, declare the function prototype before calling it.

But it is available via on 4.8 . .

To test I added to mainwindow.h (before the namespace and class stuff)

#ifdef __APPLE__
#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
// http://doc.qt.io/qt-5/qkeysequence.html#qt_set_sequence_auto_mnemonic
void qt_set_sequence_auto_mnemonic(bool b);
#endif
#endif

Unfortunately this change does nothing for me since Cmd+Q already closes the app on macOS 😁

But I also tested on Windows VM and seems to work fine . .

Yeah. It would be better, if you could fix this. Thank you.