You are not logged in.

Pages: 1

#1 2021-12-11 14:01:43

ankit
Member
Registered: 2021-04-07
Posts: 11

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

I got this error after i installed windows in another partition and ran grub-install and grub-mkconfig for dual boot.

I can get upto sddm login screen and when I try to login I return to the same login after about 10-15 seconds.

the error part (I suppose):

```

Dec 11 10:43:18 smloy-arch lxqt-session[983]: qt.qpa.xcb: could not connect to display :0

Dec 11 10:43:18 smloy-arch lxqt-session[983]: qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.

Dec 11 10:43:18 smloy-arch lxqt-session[983]: This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

```

last 500 lines of journalctl:

https://justpaste.it/7nl1g

dmesg:

https://justpaste.it/6vjbd

Xorg.0.log:

https://justpaste.it/38wib

Offline

#2 2021-12-11 15:01:54

seth
Member
From: Won't reply 2 private help req
Registered: 2012-09-03
Posts: 77,164

Re: "qt.qpa.xcb: could not connect to display :0" error

The log shows an x11 server that started Sat Dec 11 10:43:20 2021 and ran for about 4 minutes.

Dec 11 10:42:56 smloy-arch NetworkManager[538]: <info>  [1639198676.8407] manager: startup complete
…
Dec 11 10:44:50 smloy-arch systemd-networkd-wait-online[542]: Timeout occurred while waiting for network connectivity.
…
Dec 11 10:44:50 smloy-arch reflector[1193]: [2021-12-11 10:44:50] WARNING: failed to rate http(s) download (https://archlinux.thaller.ws/community/os/x86_64/community.db): <urlopen error [Errno -2] Name or service not known>

Smells like a fucked up network configuration.
Please post the complete system journal and the output of

find /etc/systemd -type l -exec test -f {} \; -print | awk -F'/' '{ printf ("%-40s | %s\n", $(NF-0), $(NF-1)) }' | sort -f

How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

Offline

#3 2021-12-11 16:53:57

ankit
Member
Registered: 2021-04-07
Posts: 11

Re: "qt.qpa.xcb: could not connect to display :0" error

full journal:

https://pastebin.com/WdiGYqUx

output of the find command:

choose-mirror.service                    | multi-user.target.wants
dbus-org.freedesktop.network1.service    | system
dbus-org.freedesktop.nm-dispatcher.service | system
dbus-org.freedesktop.resolve1.service    | system
default.target                           | system
dirmngr.socket                           | sockets.target.wants
display-manager.service                  | system
getty@tty1.service                       | getty.target.wants
gpg-agent-browser.socket                 | sockets.target.wants
gpg-agent-extra.socket                   | sockets.target.wants
gpg-agent.socket                         | sockets.target.wants
gpg-agent-ssh.socket                     | sockets.target.wants
iwd.service                              | multi-user.target.wants
livecd-alsa-unmuter.service              | sound.target.wants
livecd-talk.service                      | multi-user.target.wants
NetworkManager.service                   | multi-user.target.wants
NetworkManager-wait-online.service       | network-online.target.wants
p11-kit-server.socket                    | sockets.target.wants
pacman-init.service                      | multi-user.target.wants
pipewire-media-session.service           | pipewire.service.wants
pipewire-pulse.socket                    | sockets.target.wants
pipewire-session-manager.service         | user
pipewire.socket                          | sockets.target.wants
reflector.service                        | multi-user.target.wants
remote-fs.target                         | multi-user.target.wants
sshd.service                             | multi-user.target.wants
systemd-networkd.service                 | multi-user.target.wants
systemd-networkd.socket                  | sockets.target.wants
systemd-networkd-wait-online.service     | network-online.target.wants
systemd-resolved.service                 | multi-user.target.wants
xdg-user-dirs-update.service             | default.target.wants

Offline

#4 2021-12-11 19:47:48

seth
Member
From: Won't reply 2 private help req
Registered: 2012-09-03
Posts: 77,164

Re: "qt.qpa.xcb: could not connect to display :0" error

…
iwd.service                              | multi-user.target.wants
…
NetworkManager.service                   | multi-user.target.wants
NetworkManager-wait-online.service       | network-online.target.wants
…
systemd-networkd.service                 | multi-user.target.wants
systemd-networkd.socket                  | sockets.target.wants
systemd-networkd-wait-online.service     | network-online.target.wants

So you've systemd-networkd, networkmanager and iwd running at the same time. Pick one, drop the others.
You'll need iwd to provide a wifi carrier for systemd-networkd and you can configure it as backend for networkmanager, but do not run it next to networkmanager.

How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

Offline

#5 2021-12-12 04:41:31

ankit
Member
Registered: 2021-04-07
Posts: 11

Re: "qt.qpa.xcb: could not connect to display :0" error

I removed network manger and iwd and kept wpa_supplicant, still it doesnot work:

new journal:
https://pastebin.com/A1tZzJsj

the output of that find command:

choose-mirror.service                    | multi-user.target.wants
dbus-org.freedesktop.network1.service    | system
dbus-org.freedesktop.resolve1.service    | system
default.target                           | system
dirmngr.socket                           | sockets.target.wants
display-manager.service                  | system
getty@tty1.service                       | getty.target.wants
gpg-agent-browser.socket                 | sockets.target.wants
gpg-agent-extra.socket                   | sockets.target.wants
gpg-agent.socket                         | sockets.target.wants
gpg-agent-ssh.socket                     | sockets.target.wants
livecd-alsa-unmuter.service              | sound.target.wants
livecd-talk.service                      | multi-user.target.wants
p11-kit-server.socket                    | sockets.target.wants
pacman-init.service                      | multi-user.target.wants
pipewire-media-session.service           | pipewire.service.wants
pipewire-pulse.socket                    | sockets.target.wants
pipewire-session-manager.service         | user
pipewire.socket                          | sockets.target.wants
reflector.service                        | multi-user.target.wants
remote-fs.target                         | multi-user.target.wants
sshd.service                             | multi-user.target.wants
systemd-networkd.service                 | multi-user.target.wants
systemd-networkd.socket                  | sockets.target.wants
systemd-networkd-wait-online.service     | network-online.target.wants
systemd-resolved.service                 | multi-user.target.wants
xdg-user-dirs-update.service             | default.target.wants

Offline

#6 2021-12-12 07:33:28

seth
Member
From: Won't reply 2 private help req
Registered: 2012-09-03
Posts: 77,164

Re: "qt.qpa.xcb: could not connect to display :0" error

Changed to "Dec 12 10:21:15 smloy-arch kglobalaccel5[1006]: qt.qpa.xcb: could not connect to display" (the DISPLAY is empty) and it also seems to only affect kglobalaccel

=> The session seems to start, though?
If not, can you login as a different user?

And the network resolution errors are gone, too.

Ceterum censeo:

I got this error after i installed windows in another partition

3rd link below

How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

Offline

#7 2021-12-12 10:21:54

ankit
Member
Registered: 2021-04-07
Posts: 11

Re: "qt.qpa.xcb: could not connect to display :0" error

I have not made any other user but same user on tty, logins fine.

I have disabled fast startup too but still the problem persists. I just get black screen but can move mouse pointer.

Any other ideas?

Offline

#8 2021-12-12 12:41:08

seth
Member
From: Won't reply 2 private help req
Registered: 2012-09-03
Posts: 77,164

Re: "qt.qpa.xcb: could not connect to display :0" error

I have not made any other user but same user on tty, logins fine.

Yeah, because that's exclusively an issue w/ your GUI session…

I just get black screen but can move mouse pointer.

If you don't get a desktop by disabling the compositor (shift+alt+f12) try
1. to log into a different TTY and there run "xterm -display :0"
2. a fresh user (as asked before) to rule out issues w/ your configuration

How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

Offline

#9 2021-12-12 15:02:42

eticre
Member
Registered: 2011-10-15
Posts: 55

Re: "qt.qpa.xcb: could not connect to display :0" error

hello
same problem using an usb wifi dongle

0e8d:7612 MediaTek Inc. MT7612U

this dongle is ,at boot, recognized as sr0 (cdrom) because have internal rom containing driver
after espell  they are recognized as wifi but system is unusable with xcb error

I resolved installing usb_modeswitch and dongle is recognized as wifi at startup

Offline

Pages: 1

Board footer

Powered by FluxBB