All of the following is on a Raspberry Pi 3 with Qt 5.3.2 (GCC 4.9.2, 32 bit).

MainWindow.h
Qt Code: 
  1. #ifndef MAINWINDOW_H
  2. #define MAINWINDOW_H
  3.  
  4. #include <QMainWindow>
  5. #include <QtSerialPort/qserialportinfo.h>
  6. #include <QtSerialPort/qserialport.h>
  7. #include <QObject>
  8. #include <QtCore/QCoreApplication>
  9. #include <QDebug>
  10. #include <QList>
  11.  
  12.  
  13.  
  14. namespace Ui {
  15. class MainWindow;
  16. }
  17.  
  18. class MainWindow : public QMainWindow
  19. {
  20.     Q_OBJECT
  21.  
  22. public:
  23.     explicit MainWindow(QWidget *parent = 0);
  24.  
  25.  
  26.     bool zaber_is_available;
  27.     ~MainWindow();
  28.  
  29. private slots:
  30.  
  31.  
  32.  
  33.     void on_Calibration_25mm_stage_move_button_clicked(int position);
  34.  
  35.     void on_Calibration_25mm_stage_home_button_clicked();
  36.  
  37.     void on_Calibration_25mm_stage_out_button_clicked();
  38.  
  39.     void on_Calibration_300mm_stage_move_button_clicked(int position);
  40.  
  41.     void on_Calibration_300mm_stage_home_button_clicked();
  42.  
  43.     void on_Shot_tab_25mm_stage_move_button_clicked(int position);
  44.  
  45.     void on_Shot_tab_25mm_stage_home_button_clicked();
  46.  
  47.     void on_Shot_tab_25mm_stage_out_button_clicked();
  48.  
  49.     void CommZaber(QString);
  50.  
  51.     void on_Calibration_25mm_slider_sliderMoved(int position);
  52.  
  53.     void on_Calibration_300mm_slider_sliderMoved(int position);
  54.  
  55.     void on_Shot_tab_25mm_slider_sliderMoved(int position);
  56.  
  57.     void on_Shot_tab_25mm_spinbox_valueChanged(int arg1);
  58.  
  59.     void on_Calibration_300mm_spinbox_valueChanged(int arg1);
  60.  
  61.     void on_Calibration_25mm_spinbox_valueChanged(int arg1);
  62.  
  63.  
  64. private:
  65.     Ui::MainWindow *ui;
  66.     QSerialPortInfo *serialPortInfo;
  67.     QSerialPort *zaber;
  68.  
  69.  
  70.     static const quint16 zaber_vendor_id = 0403;
  71.     static const quint16 zaber_product_id = 6001;
  72.  
  73. };
  74.  
  75. #endif // MAINWINDOW_H
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main.cpp
Qt Code: 
  1. #include "mainwindow.h"
  2. #include <QApplication>
  3. #include <QPushButton>
  4. #include <QSpinBox>
  5. #include <QSlider>
  6.  
  7. int main(int argc, char *argv[])
  8. {
  9.     QApplication a(argc, argv);
  10.     MainWindow w;
  11.     w.setWindowTitle("Compact 6 Radiometer Control Unit");
  12.     w.show();
  13.  
  14.  
  15.  
  16.  
  17.  
  18.  
  19.     return a.exec();
  20. }
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MainWindow.cpp
Qt Code: 
  1. #include "mainwindow.h"
  2. #include "ui_mainwindow.h"
  3. #include <QtSerialPort/qserialport.h>
  4. #include <QtSerialPort/qserialportinfo.h>
  5. #include <QObject>
  6. #include <QList>
  7. #include <QDebug>
  8. #include <QString>
  9. #include <QWidget>
  10. #include "qmath.h"
  11. #include <QIODevice>
  12.  
  13. QT_USE_NAMESPACE
  14.  
  15. char Reply_Bytes[6] ={0};
  16. qint64 maxSize = 6;
  17. int value[4];
  18. int value2[4];
  19. char position_command[6] = {0};
  20. double new_value;
  21. float conversion;
  22. float distance;
  23. const double global_x = pow(256,3);
  24. const double global_y = pow(256,2);
  25. const double global_z = pow(256,4);
  26. float input_position;
  27. int Cmd_Byte_6 = 0;
  28. int Cmd_Byte_5 = 0;
  29. int Cmd_Byte_4 = 0;
  30. int Cmd_Byte_3 = 0;
  31.  
  32. MainWindow::MainWindow(QWidget *parent) :
  33.     QMainWindow(parent),
  34.     ui(new Ui::MainWindow)
  35. {
  36.     ui->setupUi(this);
  37.  
  38.     zaber_is_available = false;
  39.  
  40.     qDebug() <<"Number of ports: "<<QSerialPortInfo::availablePorts();
  41.  
  42.     foreach(const QSerialPortInfo &serialPortInfo, QSerialPortInfo::availablePorts())
  43.     {
  44.         qDebug()<< "Name: " << serialPortInfo.portName();
  45.         qDebug()<< "Description: "<< serialPortInfo.description();
  46.         qDebug()<< "Manufacturer: " << serialPortInfo.manufacturer();
  47.         if(serialPortInfo.hasVendorIdentifier() && serialPortInfo.hasProductIdentifier())
  48.         {
  49.             qDebug() << "Has VendorID and ProductID:" << serialPortInfo.hasVendorIdentifier() <<
  50.                         "and" << serialPortInfo.hasVendorIdentifier();
  51.             if(serialPortInfo.vendorIdentifier() == zaber_vendor_id)
  52.             {
  53.                 qDebug() << "Vendor: " << serialPortInfo.vendorIdentifier();
  54.                 if(serialPortInfo.productIdentifier() == zaber_product_id)
  55.                 {
  56.                     qDebug() << "Product: " << serialPortInfo.productIdentifier();
  57.                     zaber = new QSerialPort;
  58.                     zaber_is_available = true;
  59.                 }
  60.             }
  61.         }
  62.     }
  63.  
  64.    //code removed as QDebug does not show in it and it is too long.
  65.  
  66. void MainWindow::CommZaber(QString command)
  67. {
  68.     if(zaber->isWritable()){
  69.         zaber->write(command.toStdString().c_str());
  70.     }
  71.     else{
  72.         qDebug() << "Couldn't Write to Serial";
  73.     }
  74.  
  75. }
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The error I get is as stated in the post title. The pointer for the error leads me to the library, as if the error was in the library.

I have tried adding the following to my header file to fix the issue but it did not work.
Qt Code: 
  1. class DebugClass : public QObject
  2. {
  3.     Q_OBJECT
  4. public:
  5.     explicit DebugClass(QObject *parent = 0);
  6.     friend QDebug operator<< (QDebug dbg, const DebugClass &info){
  7.         dbg.nospace() << "This is x: " <<info.x;
  8.         return dbg.maybeSpace();
  9.     }
  10.  
  11. private:
  12.     int x;
  13. };
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I have gotten this far by the good graces of Google. Any help would be greatly appreciated.