Bdtyktl

This post has been translated from German. For the original, please see the revision history.

I have written the following program in Qt Creator.

The error message refers to Ubuntu. I'm using Ubuntu 18.04 on a device with Intel i5.

I've been researching for days and have not found a solution yet.

What could be the problem and how can I fix it?

#include <QApplication>

#include <QPushButton>



int main(int argc, char* argv)

{

    QApplication app(argc, argv);

    QPushButton button("Hallo Welt und so weiter");



    button.move(250,300);

    button.show();



    return app.exec();

}

:-1: Fehler: collect2: error: ld returned 1 exit status

g++ -Wl,-rpath,/opt/Qt/5.11.1/gcc_64/lib -o HalloWelt main.o   -L/opt/Qt/5.11.1/gcc_64/lib -lQt5Widgets -lQt5Gui -lQt5Core -lGL -lpthread 

/usr/bin/x86_64-linux-gnu-ld: cannot find -lGL

Makefile:254: recipe for target 'HalloWelt' failed

collect2: error: ld returned 1 exit status

make: *** [HalloWelt] Error 1

16:12:14: Der Prozess "/usr/bin/make" wurde mit dem Rückgabewert 2 beendet.

Fehler beim Erstellen/Deployment des Projekts HalloWelt (Kit: Desktop Qt 5.11.1 GCC 64bit)

Bei der Ausführung von Schritt "Make"

16:12:14: Verstrichene Zeit: 00:00.

At first it is very strange that you have Qt in /opt.

The correct way would be to install Qt 5.9.5 and other development packages from repository:

sudo apt-get install qt5-default build-essential checkinstall 

libc6-dev libssl-dev libexpat1-dev libgl1-mesa-dev libqt4-dev 

libavcodec-dev libavutil-dev pkg-config

Then compile your program with

g++ HalloWelt.cpp $(pkg-config --cflags Qt5Widgets) $(pkg-config --libs Qt5Widgets) -fPIC -o HalloWelt

And run with

./HalloWelt

If you want to fix only -lGL error you should install one package:

sudo apt-get install libgl1-mesa-dev