Instructions for Debian 12 (Bookworm) should be in deb822 format

[4wk-]

Starting with Bookworm, it's recommended to write apt sources files in deb822 format.

Instead of actual documentation:

vi /etc/apt/sources.list.d/bookworm-backports.list

deb http://deb.debian.org/debian bookworm-backports main contrib
deb-src http://deb.debian.org/debian bookworm-backports main contrib

It should be:

vi /etc/apt/sources.list.d/bookworm-backports.sources

Types: deb deb-src
URIs: http://deb.debian.org/debian
Suites: bookworm-backports
Components: main contrib
Signed-By: /usr/share/keyrings/debian-archive-keyring.gpg

• https://manpages.debian.org/bookworm/apt/sources.list.5.en.html#DEB822-STYLE_FORMAT
• https://repolib.readthedocs.io/en/latest/deb822-format.html (RepoLib is Python-related, but I think it's still interesting)

--
Working as expected:

# apt-cache madison zfsutils-linux
zfsutils-linux | 2.2.4-1~bpo12+1 | http://deb.debian.org/debian bookworm-backports/contrib amd64 Packages

[gmelikov]

While I'm not against it, traditional format is still used and not explicitly described as deprecated.

Fun thing is that even weekly build https://cdimage.debian.org/cdimage/weekly-live-builds/amd64/iso-hybrid/ use traditional format for /etc/apt/sources.list

I propose to leave it as is for now for ease of usage (copy-pasting).

[4wk-]

You're right; even on a fresh "netinstall" Debian image, /etc/apt/sources.list file is still written in regular syntax (not deb822).
I guess /etc/apt/sources.list.d/debian.sources file is packed with Docker bookworm image (a bit "early" :))