Dependencies of QCAD on Ubuntu 26

QCAD Professional QCAD Troubleshooting and Problems
1

From a QCAD user:

QCAD Version: 3.32.9
Downloaded package (file name): qcad-3.32.9-pro-linux-qt6-x86_64.run
Operating System: Ubuntu 26.04 LTS

After installation, when trying to run QCAD, I’m getting:

QCAD version  3.32.9
Warning:  From 6.5.0, xcb-cursor0 or libxcb-cursor0 is needed to load the Qt xcb platform plugin.
10:05:26: Info:    Could not load the Qt platform plugin "xcb" in "" even though it was found.
2

Please check for missing dependencies:

cd ~/opt/qcad-3.32.9-pro-linux-qt6-x86_64
LD_LIBRARY_PATH=. ldd qcad-bin `find . -name "*.so"` | grep "not found"

You need to install the packages providing the missing libraries listed.

From your output, I can already see that at least these are missing:

xcb-cursor0
libxcb-cursor0

You can fix these with:

sudo apt install libxcb-cursor0

Pro-Tip: Let Ubuntu Find It Automatically

If you ever run into a similar issue where a program complains about a missing libsomething.so file, you can use a tool called apt-file to search for the exact package name.

Install the tool:

sudo apt install apt-file

Update its database:

sudo apt-file update

Search for the missing file:

apt-file search libxcb-cursor.so

This will tell you exactly which package you need to install.

flatpak

If you are ready to leave the dependency mess behind you, you may want to install a flatpak instead:

QCAD - QCAD Installation on Linux from Flatpak

3

Good morning andrew,

Thank you very much for your help, that fix the issue and qcad works now.

However, I did not notice an improvement in speed or reaction on big files.

Every action pops up the wait / quit dialog and it takes long time to react even to zoom or displace the drawing. It is usable for small areas and hope in the future this can improve.

Thanks again for your effort.

carlos

4

I can confirm that neither QCAD 3.32.9 nor Qt 6 address any kind of performance issues. Your files might simply be too complex for QCAD to handle. A common issue are also very dense hatch patterns or very dense line type patterns. Your file would help us to identify the problem.