Python issues on Bookworm

The latest version of Mate has Wayland support.
The objective in using XFCE was that it was only Xorg and is the GUI linucnc uses natively.
Its quite possible you are still getting bitten by things that are missing in Wayland.

Just installed and switched to XFCE, and I'm still getting the same Could not link test program to Python error.

The only thing I can think of is that I am using QTplasmac that requires  this script tobe run to install the QT dependencies

Rod, how many Python directories does your system have installed?

I've got 3, python3, python3.10, and python 3.11
python3, only has dist-packages in it, whereas 3.10 and 3.11 have what look like full installs in them.
However 3.10 has no dist-packages directory, whereas 3.11 has one, but only has two numpy directories in it.
What to me looks like all the LinuxCNC relevant stuff is in the python3 dist-packages directory (gladevcp, gmocapy, gscreen, plasmac stand out from a quick scan over the various files)

Could it be the installer is assuming Python is installed to simply python3, whereas Debian is actually installing it to version specific directories, so the LinuxCNC files are being moved to the wrong place?
If so, any idea how to fix it?
(please bear in mind my linux skills are pretty limited, so nice simple directions are preferred!)

The reason I started playing with Bookworm and Bullseye was to get away from Python 2.7 altogether. I think Linuxcnc requires Python 3.9 or above. Initially it broke when Debian moved from Python 3.9 to Python 3.10. The Linuxcnc prerequisites were relaxed on my issue report. I suspect Python > 3.10 is still OK,

I think the issue is to do with how Debian has installed Python, possibly to do with me running on Bookworm that has been upgraded from Bullseye, rather than a clean Bookworm install.

I just tried running python3 in the terminal, and it's reporting 3.10.8, which I think is what is the default option in Bullseye.
To run 3.11, I have to enter python3.11

Did you install a clean Bookworm, or upgrade from Bullseye?

This PC started with Bullseye and has seen just about every kernel released since 5.10 through to 6.0 (Not to mention Mint 17.3 in a past life)
It only became an issue with the latest bookworm deb. As its prerelease, a lot of things  can happen. eg a package might be removed from Debian due to a security concern. If Linuxcnc depends on it, Linuxcnc will be earmarked for removal unless its fixed in our code.

I don't think its a Python version error but more like something Linuxcnc is depending on has been retired.

I don't understand why its an issue for you with xfce when it works for me.

I'm getting the same python3 error trying to run Gmoccapy. I installed a clean Bookworm and followed JT's instructions to get LinuxCNC installed. There were no missing QT dependencies when I tried running the ...designer/install_script per above. Any thoughts on what else to try?

Funny, I just opened a gmocappy sim earlier today.
I still think the issue will be resolved by installing a non-wayland environment.
sudo apt-get tasksel
sudo tasksel

Install XFC, log out to the logon screen. Click on the user name field, select the gear at lower right and select xfce, then login.

You are right! I switched to xfce and gmoccapy started up. It complains about an OpenGL NullFunctionError and no lathe_option attribute, but I was able to home the machine.