Install from apt repository

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 QtPyVCP 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 – this also removes any VCPs you have installed (Probe Basic, TurboNC, MonoKrom), and reinstalling Probe Basic rewrites the core configs it ships in ~/linuxcnc/configs/, so any edits you have made to those 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-qtpyvcp

Only QtPyVCP, its VCPs and the packages installed alongside them are affected. When it finishes, sudo apt update will no longer show the “Missing key” message, QtPyVCP is installed and up to date, and it will update with new releases cleanly going forward. Then reinstall your VCP using the steps below.

Update the System

sudo apt update
sudo apt upgrade

Add the APT Repository

Run the following command. It detects your Debian release (Bookworm or Trixie) and your 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:

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

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 on your machine and your LinuxCNC configs in ~/linuxcnc/configs/ are left untouched.

Install QtPyVCP

sudo apt update
sudo apt install python3-qtpyvcp

Install a VCP

There are three VCPs in the repository. They all come from the same repository you just added, so no extra setup is needed:

sudo apt install python3-probe-basic
sudo apt install python3-monokrom
sudo apt install python3-turbonc

Updating

QtPyVCP and the VCPs update through normal APT upgrades:

sudo apt update
sudo apt upgrade

Uninstall

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.