Channel authors can indicate the primary URL of their channel’s Git repository in the .guix-channel file, like so:
(channel (version 0) (url "https://example.org/guix.git"))
guix pull to determine whether it is pulling code
from a mirror of the channel; when that is the case, it warns the user
that the mirror might be stale and displays the primary URL. That way,
users cannot be tricked into fetching code from a stale mirror that does
not receive security updates.
This feature only makes sense for authenticated repositories, such as
guix channel, for which
guix pull ensures
the code it fetches is authentic.