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How start compiler in Ubuntu 20

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  • M Offline
    M Offline
    Mikeeeeee
    wrote on last edited by
    #7

    I don't understand you. Do I need to register this in the console?

    JonBJ 1 Reply Last reply
    0
    • M Mikeeeeee

      I don't understand you. Do I need to register this in the console?

      JonBJ Offline
      JonBJ Offline
      JonB
      wrote on last edited by JonB
      #8

      @Mikeeeeee
      You need to do just what @mrjj stated:

      1. Open a console/terminal.
      2. Type: export QT_DEBUG_PLUGINS=1
      3. Type the path to the Qt Creator executable to run it.

      Because it has been run from a shell with that environment variable exported, you will get debug output showing you where it's looking for what, to diagnose your problem.

      1 Reply Last reply
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      • M Offline
        M Offline
        Mikeeeeee
        wrote on last edited by
        #9

        @JonB said in How start compiler in Ubuntu 20:

        export QT_DEBUG_PLUGINS = 1

        this

        export QT_DEBUG_PLUGINS = 1
        

        return errors:

        bash: export: «=»: this is an invalid identifier
        bash: export: «1»: this is an invalid identifier
        
        
        JonBJ 1 Reply Last reply
        0
        • M Mikeeeeee

          @JonB said in How start compiler in Ubuntu 20:

          export QT_DEBUG_PLUGINS = 1

          this

          export QT_DEBUG_PLUGINS = 1
          

          return errors:

          bash: export: «=»: this is an invalid identifier
          bash: export: «1»: this is an invalid identifier
          
          
          JonBJ Offline
          JonBJ Offline
          JonB
          wrote on last edited by
          #10

          @Mikeeeeee said in How start compiler in Ubuntu 20:
          I just copied what @mrjj typed. Correct is to remove the spaces:

          export QT_DEBUG_PLUGINS=1
          

          If it had been me, I would have typed man bash and searched for export for myself:

          export [-fn] [name[=word]] ...

          1 Reply Last reply
          3
          • M Offline
            M Offline
            Mikeeeeee
            wrote on last edited by
            #11

            I write this in folder "Qt", but qt did not issue any new errors. Still, maybe this is because the installer might not have downloaded the files?

            JonBJ 1 Reply Last reply
            0
            • M Mikeeeeee

              I write this in folder "Qt", but qt did not issue any new errors. Still, maybe this is because the installer might not have downloaded the files?

              JonBJ Offline
              JonBJ Offline
              JonB
              wrote on last edited by
              #12

              @Mikeeeeee
              Prior to the qt.qpa.plugin: Could not load ... error message, because of the environment variable you should have output (in the terminal) on where it looked for plugin xcb but failed to find it.

              1 Reply Last reply
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              • M Offline
                M Offline
                Mikeeeeee
                wrote on last edited by Mikeeeeee
                #13

                It doesn't issue any more errors.
                I have only this build log:

                /home/admin1/Qt/5.15.0/gcc_64/bin/uic ../test/mainwindow.ui -o ui_mainwindow.h
                g++ -c -pipe -g -std=gnu++11 -Wall -Wextra -D_REENTRANT -fPIC -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../test -I. -I../../Qt/5.15.0/gcc_64/include -I../../Qt/5.15.0/gcc_64/include/QtWidgets -I../../Qt/5.15.0/gcc_64/include/QtGui -I../../Qt/5.15.0/gcc_64/include/QtCore -I. -isystem /usr/include/libdrm -I. -I../../Qt/5.15.0/gcc_64/mkspecs/linux-g++ -o main.o ../test/main.cpp
                g++ -pipe -g -std=gnu++11 -Wall -Wextra -dM -E -o moc_predefs.h ../../Qt/5.15.0/gcc_64/mkspecs/features/data/dummy.cpp
                g++ -c -pipe -g -std=gnu++11 -Wall -Wextra -D_REENTRANT -fPIC -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../test -I. -I../../Qt/5.15.0/gcc_64/include -I../../Qt/5.15.0/gcc_64/include/QtWidgets -I../../Qt/5.15.0/gcc_64/include/QtGui -I../../Qt/5.15.0/gcc_64/include/QtCore -I. -isystem /usr/include/libdrm -I. -I../../Qt/5.15.0/gcc_64/mkspecs/linux-g++ -o mainwindow.o ../test/mainwindow.cpp
                /home/admin1/Qt/5.15.0/gcc_64/bin/moc -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB --include /home/admin1/QtProjects/build-test-Desktop_Qt_5_15_0_GCC_64bit-Debug/moc_predefs.h -I/home/admin1/Qt/5.15.0/gcc_64/mkspecs/linux-g++ -I/home/admin1/QtProjects/test -I/home/admin1/Qt/5.15.0/gcc_64/include -I/home/admin1/Qt/5.15.0/gcc_64/include/QtWidgets -I/home/admin1/Qt/5.15.0/gcc_64/include/QtGui -I/home/admin1/Qt/5.15.0/gcc_64/include/QtCore -I. -I/usr/include/c++/9 -I/usr/include/x86_64-linux-gnu/c++/9 -I/usr/include/c++/9/backward -I/usr/lib/gcc/x86_64-linux-gnu/9/include -I/usr/local/include -I/usr/include/x86_64-linux-gnu -I/usr/include ../test/mainwindow.h -o moc_mainwindow.cpp
                g++ -c -pipe -g -std=gnu++11 -Wall -Wextra -D_REENTRANT -fPIC -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../test -I. -I../../Qt/5.15.0/gcc_64/include -I../../Qt/5.15.0/gcc_64/include/QtWidgets -I../../Qt/5.15.0/gcc_64/include/QtGui -I../../Qt/5.15.0/gcc_64/include/QtCore -I. -isystem /usr/include/libdrm -I. -I../../Qt/5.15.0/gcc_64/mkspecs/linux-g++ -o moc_mainwindow.o moc_mainwindow.cpp
                g++ -Wl,-rpath,/home/admin1/Qt/5.15.0/gcc_64/lib -o test main.o mainwindow.o moc_mainwindow.o   /home/admin1/Qt/5.15.0/gcc_64/lib/libQt5Widgets.so /home/admin1/Qt/5.15.0/gcc_64/lib/libQt5Gui.so /home/admin1/Qt/5.15.0/gcc_64/lib/libQt5Core.so -lGL -lpthread   
                
                JonBJ 1 Reply Last reply
                0
                • M Mikeeeeee

                  It doesn't issue any more errors.
                  I have only this build log:

                  /home/admin1/Qt/5.15.0/gcc_64/bin/uic ../test/mainwindow.ui -o ui_mainwindow.h
                  g++ -c -pipe -g -std=gnu++11 -Wall -Wextra -D_REENTRANT -fPIC -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../test -I. -I../../Qt/5.15.0/gcc_64/include -I../../Qt/5.15.0/gcc_64/include/QtWidgets -I../../Qt/5.15.0/gcc_64/include/QtGui -I../../Qt/5.15.0/gcc_64/include/QtCore -I. -isystem /usr/include/libdrm -I. -I../../Qt/5.15.0/gcc_64/mkspecs/linux-g++ -o main.o ../test/main.cpp
                  g++ -pipe -g -std=gnu++11 -Wall -Wextra -dM -E -o moc_predefs.h ../../Qt/5.15.0/gcc_64/mkspecs/features/data/dummy.cpp
                  g++ -c -pipe -g -std=gnu++11 -Wall -Wextra -D_REENTRANT -fPIC -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../test -I. -I../../Qt/5.15.0/gcc_64/include -I../../Qt/5.15.0/gcc_64/include/QtWidgets -I../../Qt/5.15.0/gcc_64/include/QtGui -I../../Qt/5.15.0/gcc_64/include/QtCore -I. -isystem /usr/include/libdrm -I. -I../../Qt/5.15.0/gcc_64/mkspecs/linux-g++ -o mainwindow.o ../test/mainwindow.cpp
                  /home/admin1/Qt/5.15.0/gcc_64/bin/moc -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB --include /home/admin1/QtProjects/build-test-Desktop_Qt_5_15_0_GCC_64bit-Debug/moc_predefs.h -I/home/admin1/Qt/5.15.0/gcc_64/mkspecs/linux-g++ -I/home/admin1/QtProjects/test -I/home/admin1/Qt/5.15.0/gcc_64/include -I/home/admin1/Qt/5.15.0/gcc_64/include/QtWidgets -I/home/admin1/Qt/5.15.0/gcc_64/include/QtGui -I/home/admin1/Qt/5.15.0/gcc_64/include/QtCore -I. -I/usr/include/c++/9 -I/usr/include/x86_64-linux-gnu/c++/9 -I/usr/include/c++/9/backward -I/usr/lib/gcc/x86_64-linux-gnu/9/include -I/usr/local/include -I/usr/include/x86_64-linux-gnu -I/usr/include ../test/mainwindow.h -o moc_mainwindow.cpp
                  g++ -c -pipe -g -std=gnu++11 -Wall -Wextra -D_REENTRANT -fPIC -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../test -I. -I../../Qt/5.15.0/gcc_64/include -I../../Qt/5.15.0/gcc_64/include/QtWidgets -I../../Qt/5.15.0/gcc_64/include/QtGui -I../../Qt/5.15.0/gcc_64/include/QtCore -I. -isystem /usr/include/libdrm -I. -I../../Qt/5.15.0/gcc_64/mkspecs/linux-g++ -o moc_mainwindow.o moc_mainwindow.cpp
                  g++ -Wl,-rpath,/home/admin1/Qt/5.15.0/gcc_64/lib -o test main.o mainwindow.o moc_mainwindow.o   /home/admin1/Qt/5.15.0/gcc_64/lib/libQt5Widgets.so /home/admin1/Qt/5.15.0/gcc_64/lib/libQt5Gui.so /home/admin1/Qt/5.15.0/gcc_64/lib/libQt5Core.so -lGL -lpthread   
                  
                  JonBJ Offline
                  JonBJ Offline
                  JonB
                  wrote on last edited by JonB
                  #14

                  @Mikeeeeee
                  I don't understand. Your output now shows a compilation. I thought your problem as reported by you was when you tried to start an application:

                  qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
                  This application failed to start ....

                  I have not seen you reproduce that error message with the environment variable switched on.

                  1 Reply Last reply
                  0
                  • M Offline
                    M Offline
                    Mikeeeeee
                    wrote on last edited by
                    #15

                    This error persists. The error was always there and never changed.

                    1 Reply Last reply
                    0
                    • SGaistS Offline
                      SGaistS Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on last edited by
                      #16

                      That's why we are asking you to start your application with the QT_DEBUG_PLUGINS environment variable set so that it provides more information at run time about what is happening to the xcb plugin.

                      Interested in AI ? www.idiap.ch
                      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                      1 Reply Last reply
                      0
                      • M Offline
                        M Offline
                        Mikeeeeee
                        wrote on last edited by
                        #17

                        I started using QT_DEBUG_PLUGINS, but nothing has changed. QT_DEBUG_PLUGINS need to be registered in the "Qt" folder?

                        1 Reply Last reply
                        0
                        • SGaistS Offline
                          SGaistS Offline
                          SGaist
                          Lifetime Qt Champion
                          wrote on last edited by
                          #18

                          How are you using exactly ?

                          Interested in AI ? www.idiap.ch
                          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                          1 Reply Last reply
                          1
                          • M Offline
                            M Offline
                            Mikeeeeee
                            wrote on last edited by
                            #19

                            I write in folder "Qt" in console

                            export QT_DEBUG_PLUGINS=1
                            
                            
                            1 Reply Last reply
                            0
                            • SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by
                              #20

                              The folder has no influence on that environment variable. And are you starting your application from the same terminal were you defined the variable ?

                              Interested in AI ? www.idiap.ch
                              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                              1 Reply Last reply
                              0
                              • M Offline
                                M Offline
                                Mikeeeeee
                                wrote on last edited by
                                #21

                                I am restarted Qt.
                                Maybe I'm not there to change this variable. Explain in which folder I need to change this variable?

                                JonBJ 1 Reply Last reply
                                0
                                • SGaistS Offline
                                  SGaistS Offline
                                  SGaist
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #22

                                  As I already said: the folder has absolutely nothing to do with the environnement variable.

                                  What do you mean by your restarted Qt ?

                                  Interested in AI ? www.idiap.ch
                                  Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                  1 Reply Last reply
                                  0
                                  • M Mikeeeeee

                                    I am restarted Qt.
                                    Maybe I'm not there to change this variable. Explain in which folder I need to change this variable?

                                    JonBJ Offline
                                    JonBJ Offline
                                    JonB
                                    wrote on last edited by JonB
                                    #23

                                    @Mikeeeeee
                                    This really isn't very hard. You originally showed

                                    qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
                                    This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
                                    
                                    Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-
                                    

                                    You ran a program to get this. I don't know whether it was Qt Creator or your own application, but it was one of them, whichever. Right?

                                    As we have already told you:

                                    1. Open a console/terminal.
                                    2. Type: export QT_DEBUG_PLUGINS=1
                                    3. Type the path to Qt Creator or your own executable to run it. Whichever one caused your original error.

                                    At this point you should get your error again, but this time the environment variable should cause debug output, stating which it can't load "xcb".

                                    1 Reply Last reply
                                    2
                                    • M Offline
                                      M Offline
                                      Mikeeeeee
                                      wrote on last edited by Mikeeeeee
                                      #24

                                      @JonBWhere and how do I specify the path to Qt Creator? Please provide a full example of using QT_DEBUG_PLUGINS.
                                      And maybe the QT_DEBUG_PLUGINS plugin doesn't work either?

                                      JonBJ 1 Reply Last reply
                                      0
                                      • M Mikeeeeee

                                        @JonBWhere and how do I specify the path to Qt Creator? Please provide a full example of using QT_DEBUG_PLUGINS.
                                        And maybe the QT_DEBUG_PLUGINS plugin doesn't work either?

                                        JonBJ Offline
                                        JonBJ Offline
                                        JonB
                                        wrote on last edited by JonB
                                        #25

                                        @Mikeeeeee
                                        I have provided a full example. I have given you the exact steps. I would expect any developer to be able to follow them easily. I leave it to you.

                                        M 1 Reply Last reply
                                        1
                                        • JonBJ JonB

                                          @Mikeeeeee
                                          I have provided a full example. I have given you the exact steps. I would expect any developer to be able to follow them easily. I leave it to you.

                                          M Offline
                                          M Offline
                                          Mikeeeeee
                                          wrote on last edited by
                                          #26

                                          @JonB Please explain point 3. It is not clear how, where, or why to record the path.

                                          jsulmJ 1 Reply Last reply
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