I've been having problems getting Mandos to work, so I'm trying to update it to the latest version on my RPi 2 Model B running Raspian 11 (bullseye).

If I run apt-get update with the following lines in /etc/apt/sources.list

deb https://ftp.recompile.se/pub/mandos/debian bullseye-backports main

deb-src https://ftp.recompile.se/pub/mandos/debian bullseye-backports main

I get an error about the signature being invalid, and if I comment out those lines and create /etc/apt/sources.list.d/mandos.sources as shown here for bullseye Mandos (recompile.se) and download the key, apt-get update says that the repository doesn't support armhf architecture.

Can someone help me with this please, as I really need to get Mandos working first before setting up anything else on my server?

I've pasted the full output here Update Mandos errors - Pastebin.com