Probe Basic Trixie APT Develop Install

Warning

Seeing a “Missing key” warning or error when you update? Start here.

Older versions of these instructions installed the wrong signing key. If sudo apt update shows a line like this:

Missing key 50F874571F20C5B0BA225E2F0CDFCCE0388CFA48, which is needed to verify signature.

If you are trying to update and are seeing this warning/error message, the following line will correct the situation by completely removing and reinstalling Probe Basic and its required keyrings cleanly, to resolve the issue going forward.

Please be sure any of your configuration files are backed up before running it – installing rewrites the configs shipped with Probe Basic in ~/linuxcnc/configs/, so any edits you have made to the core Probe Basic shipped configs will be overwritten.

Copy this, paste it into a terminal, and press Enter:

curl -fsSL https://repository.qtpyvcp.com/uninstall.sh | sudo sh && curl -fsSL https://repository.qtpyvcp.com/install.sh | sudo sh && sudo apt install -y python3-probe-basic

Only Probe Basic, QtPyVCP and the packages installed alongside them are affected. When it finishes, sudo apt update will no longer show the “Missing key” message, Probe Basic is installed and up to date – you do not need to follow the steps below – and it will update with new releases cleanly going forward.

Probe Basic APT development install guide for Debian 13 Trixie

Important Requirements

Probe Basic is currently designed for 1920x1080 screen sizes only.

Probe Basic requires graphics hardware that supports OpenGL 3.2 and OpenGL Shading Language (GLSL) 1.50 or later.

LinuxCNC must be installed before installing QtPyVCP and Probe Basic packages.

Installation Steps

1. Download the LinuxCNC Debian 13 Trixie PREEMPT-RT ISO

Download from:

https://www.linuxcnc.org/iso/linuxcnc_2.9.8-amd64.hybrid.iso

This Debian 13 Trixie ISO installs Debian with the required PREEMPT-RT kernel and LinuxCNC uspace package.

2. Update the system

sudo apt update
sudo apt upgrade

3. Install LinuxCNC (if not installed)

sudo apt install linuxcnc-uspace

4. Add the Trixie develop APT repository

Run the following command. It detects your Debian release and architecture (AMD64 or ARM64) and configures the correct repository and signing key for you:
curl -fsSL https://repository.qtpyvcp.com/install.sh | sudo sh
Note

Do not add the repository by hand. Adding the wrong suite for your Debian release installs packages built for the wrong Qt version, and putting the signing key in the wrong place causes apt update to fail with a “Missing key” error.
Warning

If apt update already reports a Missing key 50F874571F20C5B0BA225E2F0CDFCCE0388CFA48 error, your machine has an old or incomplete repository configuration. Clear it out first, then run the install command above:
curl -fsSL https://repository.qtpyvcp.com/uninstall.sh | sudo sh
This removes only this repository’s configuration, keys and packages. Other repositories and your LinuxCNC configs in ~/linuxcnc/configs/ are left untouched.

5. Update repositories

sudo apt update

6. Install QtPyVCP and Probe Basic

sudo apt install python3-qtpyvcp
sudo apt install python3-probe-basic

Updating and Configuration

Probe Basic and QtPyVCP update through normal APT upgrades.
sudo apt update
sudo apt upgrade

Uninstallation

To completely remove QtPyVCP and all VCPs (Probe Basic, TurboNC, MonoKrom), along with the APT repository and its signing key, run:
curl -fsSL https://repository.qtpyvcp.com/uninstall.sh | sudo sh
This works even if apt update is currently failing. It removes only this repository’s packages, sources and keys – other repositories on your machine, and your LinuxCNC configs in ~/linuxcnc/configs/, are left untouched.

To reinstall afterwards:
curl -fsSL https://repository.qtpyvcp.com/install.sh | sudo sh
sudo apt install python3-probe-basic
Probe Basic and QtPyVCP are now fully removed. Your LinuxCNC installation is unaffected.