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

JonB

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.

SSJCarti

@JonB alright thank you ill look for that

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. 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

SSJCarti

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

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?

SSJCarti

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

Pablo J. Rogina

@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.

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.

Messiah

@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!

tosh_45

This post is deleted!