A few months ago it was reported to me that several subscribers had issues when trying to perform updates on their incus servers. You should always keep your incus server updated to the latest version.
If you have this error, you will see it when trying to update your repositories.
sudo apt update
The reason for this is that the repository key had been changed and was not properly updated. The error during “sudo apt update” looks roughly like this:
Hit:1 http://security.ubuntu.com/ubuntu noble-security InRelease
Hit:2 http://us.archive.ubuntu.com/ubuntu noble InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu noble-updates InRelease
Get:4 https://pkgs.zabbly.com/incus/stable noble InRelease [8,950 B]
Hit:5 http://us.archive.ubuntu.com/ubuntu noble-backports InRelease
Err:4 https://pkgs.zabbly.com/incus/stable noble InRelease
The following signatures were invalid: EXPKEYSIG 82CC8797C838DCFD Zabbly Kernel Builds <info@zabbly.com>
Hit:6 https://ppa.launchpadcontent.net/zhangsongcui3371/fastfetch/ubuntu noble InRelease
Fetched 8,950 B in 1s (11.2 kB/s)
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
115 packages can be upgraded. Run 'apt list --upgradable' to see them.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://pkgs.zabbly.com/incus/stable noble InRelease: The following signatures were invalid: EXPKEYSIG 82CC8797C838DCFD Zabbly Kernel Builds <info@zabbly.com>
W: Failed to fetch https://pkgs.zabbly.com/incus/stable/dists/noble/InRelease The following signatures were invalid: EXPKEYSIG 82CC8797C838DCFD Zabbly Kernel Builds <info@zabbly.com>
W: Some index files failed to download. They have been ignored, or old ones used instead.
To fix this, remove the old expired key:
sudo rm /etc/apt/keyrings/zabbly.asc 2>/dev/null
Create a key folder and download the new key (the -p means create the folder only if it does not exist).
sudo mkdir -p /etc/apt/keyrings
sudo curl -fsSL https://pkgs.zabbly.com/key.asc -o /etc/apt/keyrings/zabbly.asc
Adjust the permissions properly.
sudo chmod 644 /etc/apt/keyrings/zabbly.asc
Now, updating your incus system should occur without errors.
sudo apt update
Finally, accept all of your updates and your incus server will be properly updated to the latest version.
sudo apt upgrade -y