Having eventually got around to trying out incus and planning to migrate from LXC/LXD, I am disappointed to report that the basic installation instructions do not work for a fairly vanilla Ubuntu server (focal) machine:
tom@walnut:~$ sudo apt install incus
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package incus
version info:
Distributor ID: Ubuntu
Description: Ubuntu 20.04.6 LTS
Release: 20.04
Codename: focal
Note I have solved the problem but had to add the Zabbly repo to do so:
sudo mkdir -p /etc/apt/keyrings
$ sudo curl -fsSL https://pkgs.zabbly.com/key.asc -o /etc/apt/keyrings/zabbly.asc
$ sudo vi /etc/apt/sources.list.d/zabbly-incus-stable.sources
adding:
Enabled: yes
Types: deb
URIs: https://pkgs.zabbly.com/incus/stable
Suites: focal
Components: main
Signed-By: /etc/apt/keyrings/zabbly.asc
$ sudo apt update
$ sudo apt install incus