qt.qpa.xcb: could not connect to display

SGaist

Did you test other Qt based applications ?

jarvis

Well not yet

jarvis

Is there any way to restore libqxcb.so this file is missing.

SGaist

You deleted it from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/ ?

jarvis

@SGaist I have it now
still facing the same issue

jarvis

can any symbolic link solve this issue?

SGaist

No

As requested did you check other Qt application ?
What desktop environment are you using ?

jarvis

Well i am on windows 10 with enabled subsystem kali linux.
"sudo apt-get install wireshark-common" was the command which I used,
it downloads all the lib as well automatically which I mentioned above.

SGaist

That's the kind of details that is important. A full blown Linux system or the Windows Linux subsystem is not exactly the same.

AFAIK, they currently don't provide direct support for X11, you may have to install a tool like Xming for that.

jarvis

Well I have installed Xming. Could you please help me with this

qt.qpa.xcb: X server does not support XInput 2
failed to get the current screen resources
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-jarvis'
Failed to connect to generic netlink.
The X11 connection broke: I/O error (code 1)
XIO: fatal IO error 2 (No such file or directory) on X server ":0"
after 364 requests (364 known processed) with 0 events remaining.

SGaist

I can currently go further as I don't have a Windows machine at hand.

jarvis

Well, I have installed VcXsrv instead of Xming and now Wireshark is working just as expected.

Thanks @SGaist

Networkyy

Hello i have this message while trying to downgrde ubuntu 20.04 to 18.04

E: The repository 'https://packages.sury.org/php focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://download.opensuse.org/repositories/home:/strycore/xUbuntu_16.04 Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

jsulm

@Networkyy How is your issue related to this thread?
It is not even clear to me how it is related to Qt at all...

ZainlessBrombie

FYI I had this issue when I had ssh-ed into localhost for port forwarding and tried to start it from there. A fresh terminal worked.
What I am trying to say is: Check if your $DISPLAY ist set correctly for the process and that it can communicate.

John.M T

hi guys,
I have the same error when issuing the following command:
ros2 run turtlesim turtlesim_node

My environment:
Running ubuntu20.04 server with ROS2 foxy desktop on Raspberry Pi 4.
Using windows10 putty ssh to access raspberry pi 4 and login into its ubuntu,
and issued the command "ros2 run turtlesim turtlesim_node"

Error message:

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.
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, xcb.

Please advise.
Thanks.

JonB

@John-M-T
Duplicate post of your https://forum.qt.io/topic/134114/error-when-launching-rqt.