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

[jonathan.taylor]

I just spun up a fresh Ubuntu 23.10 box with default options selected. From there, I tried installing Qt first thing.

I couldn't launch the Qt Maintenance tool / installer until I did this:

sudo apt-get install -y build-essential libx11-xcb-dev libglu1-mesa-dev libxcb-xinerama0

After installation, I still couldn't launch Creator, running into error "qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found."

So, I found this web page (which appears to be for the benefit of Stamford students working on something or another I didn't bother trying to figure out) on how to install Qt on Linux: https://web.stanford.edu/dept/cs_edu/resources/qt/install-linux They aren't explicit about the Qt version the instructions at targeting, but there is a screenshot showing v6.5. I was aiming for v6.6.1 using Creator v12.0.1 and this worked for that as well.

That link says before doing anything (including running the installer) do this:

sudo apt-get update && sudo apt-get upgrade

That's obvious, of course, since it's the first step to most every such problem!

Then, they say do this:

sudo apt-get -y install build-essential openssl libssl-dev libssl1.0 libgl1-mesa-dev libqt5x11extras5 '^libxcb.*-dev' libx11-xcb-dev libglu1-mesa-dev libxrender-dev libxi-dev libxkbcommon-dev libxkbcommon-x11-dev

Once I ran that, the problem was resolved!

This is a shotgun approach, which I did rather blindly (as is common to do with cutting & pasting suggested solutions into Linux terminals when we just want to move forward without a deep dive!). I'm not sure that all of that is really needed (like qt 5 stuff?). It seems likely those are all the dependencies from whatever specifically those students needed for their project. If anyone wants to try this one-by-one and confirm the exact minimum requirements, that would be great! I figure I'll do that at some point, but not today...

[Taufamozai]

This post is deleted!

[_APM_]

root@beaglebone-yocto:/# cd usr/bin
root@beaglebone-yocto:/usr/bin# ./calculator
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: minimal, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, xcb.

Aborted
root@beaglebone-yocto:/usr/bin#
i got same error,sir can you explain what is the error ?

[jsulm]

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

i got same error,sir can you explain what is the error ?

Is X11 server running?

[StevenlAFl]

I got this error when loading a QT6 program that didn't ship the required QT6 plugins. Instead, the plugin package loaded was a QT5 one, so there was a mismatch.

apt-get install qt6-qpa-plugins will install the libqxcb.so file required along with libqeglfs.so, libqminimalegl.so, libqoffscreen.so, libqvnc.so, libqlinuxfb.so, libqminimal.so and libqvkkhrdisplay.so.

[ami01]

same error
trying to run autolabelimg on my local machine
github repo - https://github.com/wufan-tb/AutoLabelImg

while doing the same the error I am getting continuously while trying to open the software is -
(ano) workstation@workstation-HP-Z4-G4-Workstation:~/AutoLabelImg$ python labelImg.py
QObject::moveToThread: Current thread (0x5616f4c8c8c0) is not the object's thread (0x5616f9c826f0).
Cannot move to target thread (0x5616f4c8c8c0)

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt/plugins" 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: xcb, eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, webgl.

Aborted (core dumped)

have tried reinstalling libxcb, i have tried export Qt platform plugin set command also, have tried the famous sudo apt-get install libxcb-xinerama0 command also, nothing is helping

using ubuntu 20.04, can someone please help

[jsulm]

@ami01 You should really use the search function in this forum. This is asked very often.
To debug plug-in problems like yours do: set QT_DEBUG_PLUGINS env variable before ruinning your app, then inspect (or post here) its output. See https://doc.qt.io/qt-6/debug.html for details.

[jsulm]

@ami01 I laready provided this information to you here: https://forum.qt.io/topic/148718/qt-qpa-plugin-could-not-load-the-qt-platform-plugin-xcb-in-even-though-it-was-found/6
Did you actually try that? If not - why?

[ami01]

@jsulm
I did try and now my terminal is showing the message -
(ano) workstation@workstation-HP-Z4-G4-Workstation:~/AutoLabelImg$ python labelImg.py
QFactoryLoader::QFactoryLoader() checking directory path "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt/plugins" ...
QFactoryLoader::QFactoryLoader() checking directory path "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins" ...
QFactoryLoader::QFactoryLoader() checking directory path "/home/workstation/anaconda3/envs/ano/bin" ...
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/2to3"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/2to3-3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/2to3-3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/2to3-3.7"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/2to3-3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/2to3-3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/c_rehash"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/c_rehash' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/c_rehash' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/captoinfo"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tic'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/clear"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/clear'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/convert-caffe2-to-onnx"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/convert-caffe2-to-onnx' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/convert-caffe2-to-onnx' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/convert-onnx-to-caffe2"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/convert-onnx-to-caffe2' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/convert-onnx-to-caffe2' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/f2py"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/f2py' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/f2py' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/f2py3"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/f2py3' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/f2py3' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/f2py3.7"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/f2py3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/f2py3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/fonttools"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/fonttools' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/fonttools' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/idle3"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/idle3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/idle3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/idle3.7"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/idle3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/idle3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/imageio_download_bin"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/imageio_download_bin' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/imageio_download_bin' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/imageio_remove_bin"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/imageio_remove_bin' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/imageio_remove_bin' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/infocmp"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/infocmp'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/infotocap"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tic'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lsm2bin"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/lsm2bin' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/lsm2bin' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzcat"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/xz'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzcmp"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzdiff' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzdiff' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzdiff"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzdiff' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzdiff' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzegrep"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzfgrep"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzgrep"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzless"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzless' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzless' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzma"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/xz'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzmadec"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/lzmadec'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzmainfo"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/lzmainfo'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/lzmore"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzmore' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzmore' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/natsort"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/natsort' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/natsort' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/ncursesw6-config"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/ncursesw6-config' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/ncursesw6-config' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/normalizer"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/normalizer' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/normalizer' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/openssl"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/openssl'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pip"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pip' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pip' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pip3"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pip3' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pip3' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pydoc"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pydoc3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pydoc3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pydoc3"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pydoc3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pydoc3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pydoc3.7"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pydoc3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pydoc3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pyftmerge"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pyftmerge' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pyftmerge' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pyftsubset"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pyftsubset' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pyftsubset' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pylupdate5"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pylupdate5' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pylupdate5' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pyrcc5"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pyrcc5' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pyrcc5' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/python"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/python3.7'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/python3"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/python3.7'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/python3-config"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/python3.7m-config' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/python3.7m-config' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/python3.7"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/python3.7'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/python3.7-config"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/python3.7m-config' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/python3.7m-config' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/python3.7m"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/python3.7'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/python3.7m-config"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/python3.7m-config' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/python3.7m-config' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pyuic5"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pyuic5' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pyuic5' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pyvenv"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pyvenv-3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pyvenv-3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/pyvenv-3.7"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/pyvenv-3.7' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/pyvenv-3.7' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/reset"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tset'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/skivi"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/skivi' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/skivi' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/sqlite3"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/sqlite3'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/sqlite3_analyzer"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/sqlite3_analyzer' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/sqlite3_analyzer' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tabs"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tabs'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tclsh"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tclsh8.6'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tclsh8.6"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tclsh8.6'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tic"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tic'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tiff2fsspec"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/tiff2fsspec' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/tiff2fsspec' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tiffcomment"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/tiffcomment' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/tiffcomment' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tifffile"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/tifffile' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/tifffile' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/toe"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/toe'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/torchrun"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/torchrun' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/torchrun' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tput"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tput'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tqdm"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/tqdm' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/tqdm' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/tset"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/tset'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/ttx"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/ttx' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/ttx' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/unlzma"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/xz'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/unxz"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/xz'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/wheel"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/wheel' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/wheel' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/wish"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/wish8.6'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/wish8.6"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/wish8.6'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/x86_64-conda-linux-gnu-ld"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/x86_64-conda-linux-gnu-ld'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/x86_64-conda_cos7-linux-gnu-ld"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/x86_64-conda-linux-gnu-ld'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xz"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/xz'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzcat"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/xz'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzcmp"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzdiff' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzdiff' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzdec"
"Failed to extract plugin meta data from '/home/workstation/anaconda3/envs/ano/bin/xzdec'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzdiff"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzdiff' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzdiff' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzegrep"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzfgrep"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzgrep"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzgrep' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzless"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzless' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzless' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/bin/xzmore"
QElfParser: '/home/workstation/anaconda3/envs/ano/bin/xzmore' is not an ELF object
"'/home/workstation/anaconda3/envs/ano/bin/xzmore' is not an ELF object"
not a plugin
QFactoryLoader::QFactoryLoader() checking directory path "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt/plugins/platforms/libqxcb.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt/plugins/platforms/libqxcb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"xcb"
]
},
"archreq": 0,
"className": "QXcbIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqeglfs.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqeglfs.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"eglfs"
]
},
"archreq": 0,
"className": "QEglFSIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("eglfs")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqlinuxfb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"linuxfb"
]
},
"archreq": 0,
"className": "QLinuxFbIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqminimal.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqminimal.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"minimal"
]
},
"archreq": 0,
"className": "QMinimalIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqminimalegl.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqminimalegl.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"minimalegl"
]
},
"archreq": 0,
"className": "QMinimalEglIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqoffscreen.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqoffscreen.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"offscreen"
]
},
"archreq": 0,
"className": "QOffscreenIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqvnc.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqvnc.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"vnc"
]
},
"archreq": 0,
"className": "QVncIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwayland-egl.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwayland-egl.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"wayland-egl"
]
},
"archreq": 0,
"className": "QWaylandEglPlatformIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("wayland-egl")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwayland-generic.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwayland-generic.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"wayland"
]
},
"archreq": 0,
"className": "QWaylandIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("wayland")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwayland-xcomposite-egl.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwayland-xcomposite-egl.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"wayland-xcomposite-egl"
]
},
"archreq": 0,
"className": "QWaylandXCompositeEglPlatformIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("wayland-xcomposite-egl")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwayland-xcomposite-glx.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwayland-xcomposite-glx.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"wayland-xcomposite-glx"
]
},
"archreq": 0,
"className": "QWaylandXCompositeGlxPlatformIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("wayland-xcomposite-glx")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwebgl.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqwebgl.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"webgl"
]
},
"archreq": 0,
"className": "QWebGLIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("webgl")
QFactoryLoader::QFactoryLoader() looking at "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqxcb.so"
Found metadata in lib /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/PyQt5/Qt5/plugins/platforms/libqxcb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"xcb"
]
},
"archreq": 0,
"className": "QXcbIntegrationPlugin",
"debug": false,
"version": 331520
}

Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/home/workstation/anaconda3/envs/ano/bin/platforms" ...
loaded library "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt/plugins/platforms/libqxcb.so"
QObject::moveToThread: Current thread (0x5623c38ef7c0) is not the object's thread (0x5623c310ff40).
Cannot move to target thread (0x5623c38ef7c0)

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt/plugins" 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: xcb, eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, webgl.

Aborted (core dumped)
(ano) workstation@workstation-HP-Z4-G4-Workstation:~/AutoLabelImg$

[jsulm]

@ami01 said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

loaded library "/home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt/plugins/platforms/libqxcb.so"
QObject::moveToThread: Current thread (0x5623c38ef7c0) is not the object's thread (0x5623c310ff40).
Cannot move to target thread (0x5623c38ef7c0)

Not clear what is being moved to another thread here.
Is /home/workstation/anaconda3/envs/ano/lib/python3.7/site-packages/cv2/qt the Qt installation you want to use?

[ami01]

@jsulm yes

[agguro]

a bit late but for future use and reference. followed the ldd on the plugin and libxcursor.so wasn't found. My solution:
sudo apt install libxcb-*
and it works (Qt6 already)

[IanH222]

I have this problem and sudo apt install libxcb-* did not help:

I tried putting all of the dump in but was told it was spam, so what do you need apart from

Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
loaded library "/home/ian/.local/lib/python3.10/site-packages/cv2/qt/plugins/platforms/libqxcb.so"
QObject::moveToThread: Current thread (0x5ec7f263a1c0) is not the object's thread (0x5ec7e82491a0).
Cannot move to target thread (0x5ec7f263a1c0)

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/ian/.local/lib/python3.10/site-packages/cv2/qt/plugins" 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.

[JonB]

@IanH222 said in qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.:

QObject::moveToThread: Current thread (0x5ec7f263a1c0) is not the object's thread (0x5ec7e82491a0).
Cannot move to target thread (0x5ec7f263a1c0)

We don't know why you are getting this. Let's start with: are you using any threads, or is there anything "funny" about your Qt application?

[IanH222]

It's loaded as part of a python script, and the problem is in matplotlib code.

It looks like it's potentially a problem with PyTorch's DataLoader using threads, and then me asking matplotlib to imshow some data that was originally loaded on a different thread. But I can't go much deeper than that because the rest is all in libraries.

[JonB]

@IanH222
I know that you must not try to do any Qt UI stuff in anything but the main thread, but I don't know how that relates to whatever you are doing in matplotlib.

[IanH222]

Thanks, appreciate the help. I'll ask in the forum for this code snippet.