qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.

[Megan S]

Thanks for all the helpful info on the thread!!

I am attempting an anaconda environment creation... I don't have admin privileges on the system I'm working on. It's Ubuntu16.04.1 LTS (Xenial Xerus)"

The error I get is below. I'm assuming that because I'm using the anaconda install vs using apt-get, I can't just easily reinstall? It looks to me as if I'm missing the libxcb-xinerama.so.0 package. I checked qmake --version, the output shows Qt version 5.9.7

Thanks for any suggestions!

QLibraryPrivate::loadPlugin failed on "/export/research/analysis/human/jstephen/shared/programs/python/anaconda_072020/new/envs/mne21/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so" : "Cannot load library /export/research/analysis/human/jstephen/shared/programs/python/anaconda_072020/new/envs/mne21/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so: (libxcb-xinerama.so.0: cannot open shared object file: No such file or directory)"
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.

$ qmake --version
QMake version 3.1
Using Qt version 5.9.7 in /export/research/analysis/human/jstephen/shared/programs/python/anaconda_072020/new/envs/mne21/lib

[jsulm]

@Megan-S said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

libxcb-xinerama.so.0: cannot open shared object file: No such file or directory

So do you have libxcb-xinerama.so.0?

[mathsbloke]

@Srinivas-Reddy Many thanks, that got mine working too!

[C0K01]

@Srinivas-Reddy Many thanks!

[Jimit Rupani]

@Advig said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

1. export QT_DEBUG_PLUGINS=1

2. export PATH=$PATH:~/Qt/Tools/QtCreator/bin

3. libxcb dependency so https://unix.stackexchange.com/questions/338519/how-to-install-libxcb gave the solution.

sudo apt-get install libxcb-randr0-dev libxcb-xtest0-dev libxcb-xinerama0-dev libxcb-shape0-dev libxcb-xkb-dev

4. sudo apt-get install libxkbcommon-x11-dev

solved my problem for ubuntu 20.04. Tried reinstalling almost 3 times before the solution. Hope it helps someone

[coffeesmoke]

So, Debian 10:

1. ldd -r <for example, home dir>/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/libqxcb.so | grep libxcb-util

libxcb-util.so.1 => not found

2. Ok, continue...
   sudo find /usr/lib | grep libxcb-util
   ...
   libxcb-util.so.0.0.0
   libxcb-util.so.0.0
   libxcb-util.so.0
   , but need
   libxcb-util.so.1

3. Ok, Debian... :) Redy?
   sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1.0.0
   sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1.0
   sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1

QtCreator start complete! :))))

[stounhange7]

@coffeesmoke thanks for the help. you revived my qt on debian 10

[1init]

@coffeesmoke thank you for this i ran the debian 9 instructions after installing the updates and had this issue
i run devuan

[Malachi]

That symlink seems a little risky. Two worries:

• What happens when the actual v1+ of the actual libxcb-util attempts to install?
• Are you 100% sure Qt Creator isn't depending on a different API? Seems like a dice roll

I admit though, it's better than nothing

EDIT: A few minutes of browsing https://gitlab.freedesktop.org/xorg/lib/libxcb-util/-/blob/master/NEWS suggests that no API changes are there and that symlinking is probably API compliant in this case. Funny that Debian is 6 years behind on this lib. No judging. I know they gotta test stuff. Just funny :)

[SlySven]

Assuming that version 0 of something is a pre-first version release and that Devuan 3.0 "Beowulf" (systemd-less fork of Debian 10.0 "Buster") only has the 0.0.0 version then I guess symlinking the 0.0.0 to the 1.0.0 is the only chance we've got. I just got clobbered by this when running the Qt Creator updater from within the last version that was giving me Qt 5.15.1 that told me that there was an update available. It is a real PITA when it upgraded itself out of working...

... however this topic has worked for me.

BTW The Devuan libxcb-util 0.0.0 version libraries do date back to 20 Aug 2014!

[beetree]

@coffeesmoke

As for Debian. The correct library is found as of Debian 11. Which at the moment is in testing.

• Qt application fails to start on Debian 10 Buster because libqxcb.so requires missing libxcb-util.so.1

Symlink to a different library version is a possible workaround, but does not guarantee everything else works as expected, and as such ill advised.

[saulesquivelg]

I had the same problem after installing QT in Ubuntu 18.04, I've solved it with sudo apt install libxcp-xinerama0

[coffeesmoke]

@beetree I agree. Alternatively , a virtual machine. But if you do not want to install the VM, you need to save the changes in the notations to yourself to be able to return to the original version.

[Alexreell]

@Jimit-Rupani Thank you, the first 2 points on kali linux helped me

[Niffo]

@coffeesmoke Thank you VERY much !

[sheril]

@Srinivas-Reddy
Thanks.

[requinham]

@Lengendary Thanks, this resolve the problem for me on Ubuntu 18.04 Qt 5.15.2

[CoreDump]

Environment: Ubuntu20.10; Qt 5.15.2, VirtualBox VM:

The solution provided by @Legendary no longer works, use this instead:

$ sudo apt-get install libxcb-randr0-dev libxcb-xtest0-dev libxcb-xinerama0-dev libxcb-shape0-dev libxcb-xkb-dev

[roboTURx]

@coffeesmoke thanks a lot ~ this works for me

[Deep61803]

@Lengendary said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

ibxcb-xinerama0

Thank you, This solution helped me also.