Ubuntu QT

_volterra

Where arei definition for QT include paths in QTCreator GUI ?
2.When try example " Qt Programming - Serial Port " from YouTube i get :

:-1: error: CMakeFiles/FirstAppl.dir/mainwindow.cpp.o: in function `MainWindow::on_btnPortsInfo_clicked()': /home/pache/FirstAppl/mainwindow.cpp:19: error: undefined reference to` QSerialPortInfo::availablePorts()'
:-1: error: /home/pache/FirstAppl/mainwindow.cpp:20: undefined reference to `QSerialPortInfo::portName() const' :-1: error: CMakeFiles/FirstAppl.dir/mainwindow.cpp.o: in function` void std::_Destroy<QSerialPortInfo>(QSerialPortInfo*)':
/usr/include/c++/9/bits/stl_construct.h:98: error: undefined reference to `QSerialPortInfo::~QSerialPortInfo()'
:-1: error: collect2: error: ld returned 1 exit status
:-1: error: ninja: build stopped: subcommand failed.

mainwindow.h is :

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QtSerialPort/QSerialPortInfo>
#include <QtSerialPort/QSerialPort>

QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
private slots:
void on_btnPortsInfo_clicked();
private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

and mainwindow.cpp

#include "mainwindow.h"
#include "./ui_mainwindow.h"
#include <QDebug>

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

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

void MainWindow::on_btnPortsInfo_clicked()
{
foreach (auto &port, QSerialPortInfo::availablePorts()){
qDebug() << port.portName() ;
}
}

Christian Ehrlicher

Please properly format your code so others can read it.
When you use a class/function from a library, you also have to link against it. You are using the QSerialPortInfo class so you also must link against the library which contains it as written in the documentation.