Как просмотреть, почему крошится программа при выходе?

QT += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = Kmenu
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which as been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0

SOURCES += main.cpp\
mainwindow.cpp

HEADERS += mainwindow.h

FORMS += mainwindow.ui

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/../../../../usr/lib/release/ -lkdeui
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/../../../../usr/lib/debug/ -lkdeui
else:unix: LIBS += -L$$PWD/../../../../usr/lib/ -lkdeui

INCLUDEPATH += $$PWD/../../../../usr/include
DEPENDPATH += $$PWD/../../../../usr/include

#include
#include
#include
#include
namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:

QString fileName;

explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private slots:
void on_pushButton_clicked();

private:
Ui::MainWindow *ui;
KHelpMenu *helpMenu;
};

#endif // MAINWINDOW_H

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
helpMenu = new KHelpMenu(this);
}

MainWindow::~MainWindow()
{
delete helpMenu;
delete ui;
}
void MainWindow::on_pushButton_clicked()
{
fileName = QFileDialog::getSaveFileName(0, tr("Save File"));
qDebug() << fileName;
}