I took the time today to do a full install of ubuntu:20.04, then install rdiffweb and upgrade to 24.04 LTS. Here all the steps:
1. Install Ubuntu (I used a docker image).
2. Install Rdiffweb according to documentation:
apt install lsb-release
curl -L https://www.ikus-soft.com/archive/rdiffweb/public.key | gpg --dearmor > /usr/share/keyrings/rdiffweb-keyring.gpg
echo "deb [arch=amd64 signed-by=/usr/share/keyrings/rdiffweb-keyring.gpg] https://nexus.ikus-soft.com/repository/apt-release-$(lsb_release -sc)/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/rdiffweb.list
apt update
apt install rdiffweb
3. Upgrade all package to latest version
apt dist-upgrade -y
4. Upgrade Ubuntu to 24.04 LTS. Dont use do-release-upgrade because it's not responsible to upgrade non-ubuntu repos. So following Debian upgrade instruction:
sed -i 's/jammy/noble/g' /etc/apt/sources.list /etc/apt/sources.list.d/*.list
apt update
apt upgrade
apt dist-upgrade
apt autoremove
That's about it. Rdiffweb gets upgraded and restarted.
If you think it's useful, I could add this to the Rdiffweb documentation.