Fix Mono Repo (no release file)

The problem

A few days after I applied the fix for the apt-key deprecated, I got another error from apt

E: The repository ‘https://download.mono-project.com/repo/ubuntu stable-jammy Release’ does not have a Release file.

N: Updating from such a repository can’t be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Usually this error indicates that you are using the wrong release of your distro. My Pop!_OS is built on top of Ubuntu Jammy (22.04).

However, in this specific case, the problem is that the repository release name is stable-jammy instead of just jammy.

So, we are using the correct release name and changing it is not the solution.

The Fix

The solution I found was to add [trusted=yes] after the deb declaration in the apt source file.

sudo nano /etc/apt/sources.list.d/mono-official-stable.list

This is how it is now

deb [arch=amd64 signed-by=/usr/share/keyrings/mono.gpg trusted=yes] https://download.mono-project.com/repo/ubuntu stable-jammy main

Now it does not show the release error anymore, even though it is still accusing another error in one of the index files. But this one seems to be a server problem on their side (can’t fix it).

E: Failed to fetch https://download.mono-project.com/repo/ubuntu/dists/stable-jammy/main/binary-amd64/Packages 404 Not Found [IP: 152.199.55.200 443]
E: Some index files failed to download. They have been ignored, or old ones used instead.