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qt.qpa.xcb: could not connect to display :0

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  • S SSJCarti

    I have a VcXsrv running. Also known as XLaunch

    Pablo J. RoginaP Offline
    Pablo J. RoginaP Offline
    Pablo J. Rogina
    wrote on last edited by
    #13

    @SSJCarti said in qt.qpa.xcb: could not connect to display :0:

    I have a VcXsrv running

    According to this site:

    VcXsrv makes it possible to run Linux GUI programs installed with WSL, the Windows Subsystem for Linux. In bash for Windows, setting the DISPLAY environment variable allows WSL programs to use the Windows GUI. For instance, if VcXsrv is configured to use display number zero, the command DISPLAY=:0 etr would run the game Extreme Tux Racer

    Given that you're running VcXsrv, you may need to double check its configuration and what display it's exporting/providing to the Linux side of the Windows WSL (sorry but I don't have experience with Windows WSL to help more).

    You may also want to check the videos here about VcXsrv & Win10 Linux Subsystems

    Upvote the answer(s) that helped you solve the issue
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    • S Offline
      S Offline
      SSJCarti
      wrote on last edited by
      #14

      thank you. Is there anyone else with potential ideas?

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      • JonBJ JonB

        @SSJCarti
        It's an environment variable. export QT_DEBUG_PLUGINS=1.

        S Offline
        S Offline
        SSJCarti
        wrote on last edited by
        #15

        @JonB Do you have any ideas?

        JonBJ 1 Reply Last reply
        0
        • S SSJCarti

          @JonB Do you have any ideas?

          JonBJ Offline
          JonBJ Offline
          JonB
          wrote on last edited by
          #16

          @SSJCarti

          loaded library "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so"
          qt.qpa.xcb: could not connect to display :0
          qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
          

          I know little about, less than you or @Pablo-J-Rogina . But it does seem to me that whatever he is trying to ask/tell you about an X server --- either not running or somehow not found? --- is what is causing the problem here, given that it has said

          loaded library "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so"
          Could not load the Qt platform plugin "xcb" in "" even though it was found.

          ?

          There are many Google hits for Could not load the Qt platform plugin "xcb", and we usually find that is an absent library like libxcb-xinerama.so.0. But here I am thinking you should Google for could not load the qt platform plugin "xcb" in "" even though it was found. The "even though it was found" being key. There are a bunch of hits on that, things like XDG_RUNTIME_DIR not giving you a good X environment. If I understood any of this :) that is what I would look through.

          S 1 Reply Last reply
          0
          • JonBJ JonB

            @SSJCarti

            loaded library "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so"
            qt.qpa.xcb: could not connect to display :0
            qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
            

            I know little about, less than you or @Pablo-J-Rogina . But it does seem to me that whatever he is trying to ask/tell you about an X server --- either not running or somehow not found? --- is what is causing the problem here, given that it has said

            loaded library "/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so"
            Could not load the Qt platform plugin "xcb" in "" even though it was found.

            ?

            There are many Google hits for Could not load the Qt platform plugin "xcb", and we usually find that is an absent library like libxcb-xinerama.so.0. But here I am thinking you should Google for could not load the qt platform plugin "xcb" in "" even though it was found. The "even though it was found" being key. There are a bunch of hits on that, things like XDG_RUNTIME_DIR not giving you a good X environment. If I understood any of this :) that is what I would look through.

            S Offline
            S Offline
            SSJCarti
            wrote on last edited by
            #17

            @JonB alright thank you ill look for that

            JonBJ 1 Reply Last reply
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            • S SSJCarti

              @JonB alright thank you ill look for that

              JonBJ Offline
              JonBJ Offline
              JonB
              wrote on last edited by JonB
              #18

              @SSJCarti
              One thing: It seems to me there is a related discussion going on in https://forum.qt.io/topic/120349/run-qt-gui-application-inside-docker. I assume that Poster is not yourself too. At least, that seems to get the same message as you do:

              loaded library "/home/user/app/platforms/libqxcb.so"
              qt.qpa.xcb: could not connect to display
              qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.

              So maybe worth a look?

              EDIT @Pablo-J-Rogina has said below this would not be helpful to you, so don't! :)

              Pablo J. RoginaP 1 Reply Last reply
              0
              • JonBJ JonB

                @SSJCarti
                One thing: It seems to me there is a related discussion going on in https://forum.qt.io/topic/120349/run-qt-gui-application-inside-docker. I assume that Poster is not yourself too. At least, that seems to get the same message as you do:

                loaded library "/home/user/app/platforms/libqxcb.so"
                qt.qpa.xcb: could not connect to display
                qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.

                So maybe worth a look?

                EDIT @Pablo-J-Rogina has said below this would not be helpful to you, so don't! :)

                Pablo J. RoginaP Offline
                Pablo J. RoginaP Offline
                Pablo J. Rogina
                wrote on last edited by
                #19

                @JonB said in qt.qpa.xcb: could not connect to display :0:

                So maybe worth a look?

                I don't think the goals/environments are the same... I'd say it will mislead OP here

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                Don't ask support requests via chat/PM. Please use the forum so others can benefit from the solution in the future

                S 1 Reply Last reply
                1
                • Pablo J. RoginaP Pablo J. Rogina

                  @JonB said in qt.qpa.xcb: could not connect to display :0:

                  So maybe worth a look?

                  I don't think the goals/environments are the same... I'd say it will mislead OP here

                  S Offline
                  S Offline
                  SSJCarti
                  wrote on last edited by
                  #20

                  @Pablo-J-Rogina so is my Xlaunch a xserver?

                  Pablo J. RoginaP 1 Reply Last reply
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                  • S SSJCarti

                    @Pablo-J-Rogina so is my Xlaunch a xserver?

                    Pablo J. RoginaP Offline
                    Pablo J. RoginaP Offline
                    Pablo J. Rogina
                    wrote on last edited by
                    #21

                    @SSJCarti said in qt.qpa.xcb: could not connect to display :0:

                    is my Xlaunch a xserver?

                    Once again, you failed to provided a link to such component/application... Make life easier for the ones that may help you.

                    If you're referring to this Xlaunch, I'm not familiar with it but from its documentation it is not an X server:

                    XLaunch is a wizard to make starting X server sessions easy

                    In addition, have you checked the videos I suggested?

                    Upvote the answer(s) that helped you solve the issue
                    Use "Topic Tools" button to mark your post as Solved
                    Add screenshots via postimage.org
                    Don't ask support requests via chat/PM. Please use the forum so others can benefit from the solution in the future

                    S 1 Reply Last reply
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                    • Pablo J. RoginaP Pablo J. Rogina

                      @SSJCarti said in qt.qpa.xcb: could not connect to display :0:

                      is my Xlaunch a xserver?

                      Once again, you failed to provided a link to such component/application... Make life easier for the ones that may help you.

                      If you're referring to this Xlaunch, I'm not familiar with it but from its documentation it is not an X server:

                      XLaunch is a wizard to make starting X server sessions easy

                      In addition, have you checked the videos I suggested?

                      S Offline
                      S Offline
                      SSJCarti
                      wrote on last edited by
                      #22

                      @Pablo-J-Rogina I do not know what an xserver is, I am very new to this whole type of stuff

                      Pablo J. RoginaP 1 Reply Last reply
                      0
                      • S SSJCarti

                        @Pablo-J-Rogina I do not know what an xserver is, I am very new to this whole type of stuff

                        Pablo J. RoginaP Offline
                        Pablo J. RoginaP Offline
                        Pablo J. Rogina
                        wrote on last edited by
                        #23

                        @SSJCarti said in qt.qpa.xcb: could not connect to display :0:

                        what an xserver is

                        I guess you'll find lots of references, documentation, tutorials about the X windowing system.
                        One of the videos I linked before does a good job at describing the purpose and some details of an X server.

                        Upvote the answer(s) that helped you solve the issue
                        Use "Topic Tools" button to mark your post as Solved
                        Add screenshots via postimage.org
                        Don't ask support requests via chat/PM. Please use the forum so others can benefit from the solution in the future

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                        0
                        • B Offline
                          B Offline
                          BertChristiaens
                          wrote on last edited by
                          #24

                          In my case I was using PyQt5 in a docker container. Even though
                          i forwarded my DISPLAY variable and X11-unix path, it didn't seem to find the display.

                          The solution for me was running xhost +local:* in the terminal of the host (outside of the container), to allow the server connection to be used by the container.

                          M T 2 Replies Last reply
                          1
                          • B BertChristiaens

                            In my case I was using PyQt5 in a docker container. Even though
                            i forwarded my DISPLAY variable and X11-unix path, it didn't seem to find the display.

                            The solution for me was running xhost +local:* in the terminal of the host (outside of the container), to allow the server connection to be used by the container.

                            M Offline
                            M Offline
                            Messiah
                            wrote on last edited by
                            #25

                            @BertChristiaens I created an account just to say that this is exactly what I was looking for! After hours of sifting through online forums trying to find a solution to this problem, this is the one that worked like a charm! Thank you good sir!

                            1 Reply Last reply
                            0
                            • B BertChristiaens

                              In my case I was using PyQt5 in a docker container. Even though
                              i forwarded my DISPLAY variable and X11-unix path, it didn't seem to find the display.

                              The solution for me was running xhost +local:* in the terminal of the host (outside of the container), to allow the server connection to be used by the container.

                              T Offline
                              T Offline
                              tosh_45
                              wrote on last edited by tosh_45
                              #26
                              This post is deleted!
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