can anyone help me with this apt update issue in ubuntu 23.10?

Question

image from software update

Ign:1 https://mirror.limda.net/Ubuntu mantic InRelease                                       
Hit:2 https://dl.google.com/linux/chrome/deb stable InRelease                                
Ign:3 https://mirror.limda.net/Ubuntu mantic-updates InRelease         
Ign:4 https://mirror.limda.net/Ubuntu mantic-backports InRelease       
Ign:5 https://mirror.limda.net/Ubuntu mantic-security InRelease        
Err:6 https://mirror.limda.net/Ubuntu mantic Release                  
  404  Not Found [IP: 103.163.246.243 443]
Err:7 https://mirror.limda.net/Ubuntu mantic-updates Release
  404  Not Found [IP: 103.163.246.243 443]
Err:8 https://mirror.limda.net/Ubuntu mantic-backports Release
  404  Not Found [IP: 103.163.246.243 443]
Err:9 https://mirror.limda.net/Ubuntu mantic-security Release
  404  Not Found [IP: 103.163.246.243 443]
Get:10 https://deb.volian.org/volian scar InRelease [35.1 kB]
Err:10 https://deb.volian.org/volian scar InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A87015F3DA22D980
Reading package lists... Done
E: The repository 'https://mirror.limda.net/Ubuntu mantic 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.
E: The repository 'https://mirror.limda.net/Ubuntu mantic-updates 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.
E: The repository 'https://mirror.limda.net/Ubuntu mantic-backports Release' does not have a Release file.

Answer 1

About the volian key not available error:

Err:10 https://deb.volian.org/volian scar InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A87015F3DA22D980

The key appears to be available on https://deb.volian.org/volian/ (at https://deb.volian.org/volian/scar.key ) and also on https://keys.openpgp.org/search?q=A87015F3DA22D980

Just downloading the keyfile so apt can find it should fix that error. apt-key used to be for managing apt keys, but it's been deprecated... it's man page's Depricated section recommends this:

Recommended: Instead of placing keys into the /etc/apt/trusted.gpg.d directory, you can place them anywhere on your filesystem by using the Signed-By option in your sources.list and pointing to the filename of the key. See sources.list(5) for details. Since APT 2.4, /etc/apt/keyrings is provided as the recommended location for keys not managed by packages.

So wherever you put the key, edit it's sources.list entry to match it's location.

Or instead of doing it manually, just follow Volian's help page here that has these instructions for using their Volian repo:

echo "deb http://deb.volian.org/volian/ scar main" | sudo tee /etc/apt/sources.list.d/volian-archive-scar-unstable.list
wget -qO - https://deb.volian.org/volian/scar.key | sudo tee /etc/apt/trusted.gpg.d/volian-archive-scar-unstable.gpg > /dev/null
sudo apt update && sudo apt install python3-pyshell

---

Two possible issues about the mirror.limda.net errors:

1. From this Q about finding an updated list of repository mirrors and checking https://launchpad.net/ubuntu/+archivemirrors I don't see mirror.limda.net mentioned anywhere (even searching the html source).

2. Browsing to https://mirror.limda.net/Ubuntu doesn't seem to return anything.

   But going to https://mirror.limda.net/ shows that https://mirror.limda.net/ubuntu-archive/ is a valid link, so that link might possibly work?

I would suggest picking a different official mirror from the link in part 1. https://launchpad.net/ubuntu/+archivemirrors