After Debian 11 "bullseye" was released on August 14th, 2021, the Debian 12 "bookworm" is now the official "testing" distribution.

Why is my Debian still on bullseye, instead of automatically updating to bookworm, even my sources all point to "testing"?

Details of the steps I performed:

sudo apt update

and got several messages like:

E: Repository 'http://ftp.cz.debian.org/debian testing InRelease' changed its 'Codename' value from 'bullseye' to 'bookworm' 
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.
Do you want to accept these changes and continue updating from this repository? [y/N]

This is expectable. I accepted all questions with 'yes'. Then I did

sudo apt upgrade
sudo apt autoremove
sudo apt full-upgrade

several times in a row, so all these commands now say:

0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

My /etc/os-release still shows bullseye after the upgrade:

user@debian:~$ cat /etc/os-release | grep VERSION
VERSION="11 (bullseye)"

The testing distribution is correctly recognized as bookworm using distro-info command:

user@debian:~$ distro-info --testing

I use these sources all the time (both before upgrade and after the upgrade):

user@debian:~$ grep ^ /etc/apt/sources.list /etc/apt/sources.list.d/*
/etc/apt/sources.list:deb http://ftp.cz.debian.org/debian/ testing main contrib non-free
/etc/apt/sources.list:deb-src http://ftp.cz.debian.org/debian/ testing main contrib non-free
/etc/apt/sources.list:deb http://security.debian.org testing-security main contrib non-free
/etc/apt/sources.list:deb-src http://security.debian.org testing-security main contrib non-free
/etc/apt/sources.list:deb http://deb.debian.org/debian testing-updates main contrib non-free
/etc/apt/sources.list:deb-src http://deb.debian.org/debian testing-updates main contrib non-free
grep: /etc/apt/sources.list.d/*: No such file or directory
  • By today (2021-08-28), an update + lsb_release -a yields the wanted description Debian GNU/Linux bookworm/sid. This suggests the issue is resolved.
    – Buttonwood
    Aug 28, 2021 at 6:01

1 Answer 1


How the installed distribution names itself is determined by the base-files package, and that can’t be updated for Bookworm before Bullseye is released, which means that Bookworm carries the same version as Bullseye when it is initially created (this is true for all new suites, after the first release of a given stable suite).

The Bookworm version of the package was uploaded on August 22; you’ll see it in testing on August 28 (or shortly thereafter).

Even though your /etc/os-release refers to Debian 11, your repository configuration does mean that you are running testing. For a few days after the release, testing remains identical to the stable distribution; but once package migration is enabled, and packages start migrating from unstable to testing, it will diverge, and eventually you will see package upgrades even if base-files isn’t updated. For example, my sdl12-compat package migrated to testing on August 16.

  • ah yes, "apt policy base-files" says: " 500 ftp.zcu.cz/debian testing/main amd64 Packages" - So I migh have been too ungracious :) Thanks.
    – ethcz
    Aug 16, 2021 at 15:55
  • I mean it says: Installed: 11.1 -- Candidate: 11.1
    – ethcz
    Aug 16, 2021 at 16:21
  • Yes, you’ll know it’s for Bookworm when it has a major version 12. Aug 16, 2021 at 16:52
  • Since the index files are failing to download, would the base-files package still update to 12? However that happens, once that happens, then that would allow everything else to update? Thanks! Aug 16, 2021 at 20:03
  • @technicguy1 as far as I can tell this question doesn’t involve index files failing to download. Perhaps you could ask your own question. Aug 16, 2021 at 20:41

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