Failed to run GALog on Ubuntu 22.04

[poul1x]

I've encountered an error while running the GALog on Ubuntu 22.04:

(venv) user@user-virtual-machine:~/Documents/galog$ python3 -m galog
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, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, webgl, xcb.

Aborted (core dumped)

All installation steps before running this command were successful.

OS: Linux Ubuntu 22.04
Python version: 3.10

[poul1x]

I found a thread discussing this bug. In short, the error is likely due to some required libraries being missing.

Installing the following packages should resolve the issue:

sudo apt install \
    libxcb-icccm4 \
    libxcb-image0 \
    libxcb-keysyms1 \
    libxcb-render-util0 \
    libxcb-xinerama0 \
    libxcb-xkb1 \
    libxkbcommon-x11-0

Since library versions may vary across different Ubuntu releases, I've prepared a more flexible version of the solution that can adapt to different scenarios:

sudo apt install \
    '^libxcb-icccm[0-9]+$' \
    '^libxcb-image[0-9]+$' \
    '^libxcb-keysyms[0-9]+$' \
    '^libxcb-render-util[0-9]+$' \
    '^libxcb-xinerama[0-9]+$' \
    '^libxcb-xkb[0-9]+$' \
    '^libxkbcommon-x11-[0-9]+$'

---

If it didn't work, here's what I did to resolve the issue:

First, enable QT debug logging and run GALog.

export QT_DEBUG_PLUGINS=1
python -m galog

# Output:
# Got keys from plugin meta data ("xcb")
# QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
# Cannot load library /home/user/Documents/galog/venv/lib/python3.10/site-packages/PyQt5/Qt5/plugins/platforms/libqxcb.so: (libxcb-icccm.so.4: cannot open shared object file: No such file or directory)

The output indicates that libxcb-icccm.so is not found (and not installed). Therefore, we need to search for and install the package.

(venv) user@user-virtual-machine:~/Documents/galog$ sudo apt search libxcb-icccm
# Output
# Sorting... Done
# Full Text Search... Done
# libxcb-icccm4/jammy,now 0.4.1-1.1build2 amd64 [installed]
#   utility libraries for X C Binding -- icccm

sudo apt install libxcb-icccm4

After that, run GALog again. You may notice that another library is still missing.

python -m galog

# Output:
# Got keys from plugin meta data ("xcb")
# QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
# Cannot load library /home/user/Documents/galog/venv/lib/python3.10/site-packages/PyQt5/Qt5/plugins/platforms/libqxcb.so: (libxcb-image.so: cannot open shared object file: No such file or directory)

Repeat the same process with this library.

Eventually, after several attempts, you should have all the necessary libraries in place.