So I accidentally made a mistake causing me to have to change the signing key on the Feren OS Repositories (I deleted the original signing key for signing packages in the repositories by mistake) which means that the Feren OS Repositories had to be updated with a new signing key altogether which this time I'll try my best not to lose again...
As a consequence of this, the following issue has popped up in Feren OS when doing an 'apt update':
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:/pushing/feren-os.gitlab.io/repositories stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY (whatever the new public key is)
W: Failed to fetch file:/pushing/feren-os.gitlab.io/repositories/dists/stable/InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY (whatever the new public key is)
Fortunately, there is a really easy fix for this.
2. Run the following commands with no quotes:
sudo rm -f /usr/share/keyrings/feren-os.key
sudo wget https://gitlab.com/feren-os/feren-repositories/raw/master/repositories/public.key -O /usr/share/keyrings/feren-os.key
sudo /usr/bin/apt-key --keyring /etc/apt/trusted.gpg.d/feren-os.gpg add /usr/share/keyrings/feren-os.key
sudo apt update
You'll need to authenticate with Sudo Privileges to perform these operations, hence the need to be an administrator. If you don't know what a Sudo Password is, it's the exact same password as the password used to log in as the user it wants the '[sudo] password' for.
If done correctly, your package repositories will be refreshed and the warnings from earlier will no longer display on any package list refresh operations now.
Again, apologies for this mistake... I'll make sure it doesn't happen a second time for sure.