Qt menubar not showing - c++

Question

I'm building a simple C++ application on Mac OS X 10.9 with Qt 5.2.1 using CMake (without MOC).
I am starting the executable from the command-line. The problem is that the menu bar is not showing up at all, the Terminal menu bar is still visible but not clickable. When I switch windows temporarily and then come back to the window of this application, I at least see the standard "application" menu with "About". The "About" action is now working and shows the dialog. The toolbar button also works as expected.
What else I tried (and didn't work):
using the pre-defined menuBar()
use setMenuBar()
new menuBar(0)
menubar->setVisible(true)
When I check the isVisible() it returns false, also if I set it to visible in the line before.
I wonder whether the lack of using MOC can be the reason for this?
Below I attached a reduced example.
#include <QtGui>
#include <QtWidgets>
class MainWindow : public QMainWindow {
public:
MainWindow();
private:
void create_actions_();
void create_menus_();
void create_toolbar_();
void about_();
QMenuBar* menu_bar_;
QMenu* file_menu_;
QMenu* help_menu_;
QToolBar* file_toolbar_;
QAction* action_about_;
};
MainWindow::MainWindow() {
resize(800, 600);
create_actions_();
create_menus_();
create_toolbar_();
}
void MainWindow::create_actions_() {
action_about_ = new QAction(tr("About"), this);
connect(action_about_, &QAction::triggered, this, &MainWindow::about_);
}
void MainWindow::create_menus_() {
menu_bar_ = new QMenuBar(this);
file_menu_ = menu_bar_->addMenu(tr("&File"));
menu_bar_->addSeparator();
help_menu_ = menu_bar_->addMenu(tr("&Help"));
help_menu_->addAction(action_about_);
menu_bar_->setNativeMenuBar(true);
}
void MainWindow::create_toolbar_() {
file_toolbar_ = addToolBar(tr("File"));
file_toolbar_->addAction(action_about_);
file_toolbar_->setIconSize(QSize(16, 16));
}
void MainWindow::about_() {
QMessageBox::about(this, tr("About"), tr("FooBar"));
}
int main(int argc, char **argv) {
QApplication app(argc, argv);
MainWindow main_window;
main_window.show();
const int exit_code = app.exec();
return exit_code;
}
CMakeLists.txt
FIND_PACKAGE(Qt5Core)
FIND_PACKAGE(Qt5Gui)
FIND_PACKAGE(Qt5OpenGL)
FIND_PACKAGE(Qt5Widgets)
FIND_PACKAGE(Qt5Declarative)
FIND_PACKAGE(Qt5MacExtras)
ADD_EXECUTABLE(main main.cc)
qt5_use_modules(main Core Gui Widgets Declarative MacExtras)
Thanks a lot in advance!

Answer 1

OK, solved the problem myself. It appears you cannot add a separator to the menubar.
Removing the menu_bar_->addSeparator(); solved the problem.