Bug#1041708: apt: Manpages have wrong advice on APT::Default-Release preventing security updates

[Daniel Gröber <dxld@darkboxed.org>]

Package: apt
Version: 2.6.1
Severity: important
Tags: security
X-Debbugs-Cc: dxld@darkboxed.org, Debian Security Team <team@security.debian.org>

Dear Maintainer,

apt's manpages contain references to APT::Default-Release which give
wrong advice on how to set it in light of the changes to the
debian-security repo Codename as of bullseye[1]:

Setting APT::Default-Release to a plain codename such as "stable" or
"bookworm" will have the disastrous consequence of preventing security
updates from bein considered when upgrading.

[1]: https://www.debian.org/releases/bullseye/amd64/release-notes/ch-information.en.html#security-archive


Please update any Default-Release references with the advice from the
bullseye release-notes at [1].

Thanks,
--Daniel

PS: I think this change of debian-security Codename was a collossal
mistake and I'm looking into getting this fixed properly by changing
the codename to $codename/security but the updated advice should be
safe in the face of that change.