Error "has triggered a breakpoint" when trying to call members of QSpinBox in Debug

[donelron]

Dear d_stranz,

I posted the minimal example for better overview, however, the problem is still there, if i incorporate it into a "proper GUI application" (see below).

main.cpp:

#include <QApplication>
 
#include <TestWindow.h>
 
int main(int argc, char *argv[])
{
    int i=777;  //some random value
 
    QApplication app(argc, argv);
    TestWindow w;
    w.show();
    i= app.exec();
 
    return i;
}

#include <QApplication>

#include <TestWindow.h>

int main(int argc, char *argv[])
{
    int i=777;  //some random value

    QApplication app(argc, argv);
    TestWindow w;
    w.show();
    i= app.exec();

    return i;
}

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TestWindow.h:

#ifndef TESTWINDOW_H
#define TESTWINDOW_H
 
#include <QMainWindow>
 
namespace Ui {
class TestWindow;
}
 
class TestWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit TestWindow(QWidget *parent = 0);
    ~TestWindow();
 
private:
    Ui::TestWindow *ui;
};
 
#endif  // TESTWINDOW_H

#ifndef TESTWINDOW_H
#define TESTWINDOW_H

#include <QMainWindow>

namespace Ui {
class TestWindow;
}

class TestWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit TestWindow(QWidget *parent = 0);
    ~TestWindow();

private:
    Ui::TestWindow *ui;
};

#endif  // TESTWINDOW_H

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TestWindow.cpp:

#include "TestWindow.h"
#include "ui_TestWindow.h"
 
TestWindow::TestWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::TestWindow)
{
    ui->setupUi(this);
}
 
TestWindow::~TestWindow()
{
    delete ui;
}

#include "TestWindow.h"
#include "ui_TestWindow.h"

TestWindow::TestWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::TestWindow)
{
    ui->setupUi(this);
}

TestWindow::~TestWindow()
{
    delete ui;
}

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TestWindow.ui:

<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>TestWindow</class>
 <widget class="QWidget" name="TestWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Form</string>
  </property>
  <widget class="QSpinBox" name="spinBox">
   <property name="geometry">
    <rect>
     <x>100</x>
     <y>70</y>
     <width>42</width>
     <height>22</height>
    </rect>
   </property>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>

<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>TestWindow</class>
 <widget class="QWidget" name="TestWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Form</string>
  </property>
  <widget class="QSpinBox" name="spinBox">
   <property name="geometry">
    <rect>
     <x>100</x>
     <y>70</y>
     <width>42</width>
     <height>22</height>
    </rect>
   </property>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>

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If I run this in DEBUG, then I get the runtime error "..has triggered a breakpoint" as soon as I close the window.
If I replace the QSpinBox with a QLineEdit, then the runtime error at closing of the window disappears.
However, if I add some text to the QLineEdit while the window is open, I get the same error. It seems that the application can not handle it, if any QWidgets (like QLineEdit or QSpinBox) hold data during runtime.

I also noticed that when compiling in DEBUG, I get the warning
"Warning 1 warning LNK4075: ignoring '/INCREMENTAL' due to '/LTCG' specification C:\svn\SpielwieseQt\_build_x64_vc11\LINK". Not sure, if this is related to the problem I described.

Any ideas on how to approach this?

[d_stranz]

When I create a new project and paste your code into the UI file, it runs just fine. This is with VS 2013, Qt 5.4.1. I doubt the VS version has anything to do with it. Are you sure you are linking with the same version of Qt that is loaded at run-time? That is, is your PATH environment variable pointing to the same location for Qt runtime DLLs as you are specifying in your linker options?

[donelron]

It turned out that it was a problem with the 5.4.1 build of the lib. Using another build (Qt5.5) solved the problem.

[Mr_workalota787]

how do you change the build of qt ??

[ChrisW67]

Use the Maintenance Tool to download a different version of the Qt libraries, or download Qt and build from source if that's how you get Qt, and rebuild your application using it.

Hijacking a five year old thread is not the best way to get attention.