Bug#1051087: reportbug: linux-headers-amd64 from bullseye-backports cannot be installed (unmet dependencies)

[Laurent BRULET <spm-debian@lebernie.net>]

Package: linux-headers-amd64
Version: 6.1.27-1~bpo11+1
Severity: important
X-Debbugs-Cc: spm-debian@lebernie.net

Dear Maintainer,

It seems that linux-headers-amd64 package (6.1.27-1~bpo11+1) from
bullseye-backports cannot be installed.  Because it depends on
linux-headers-6.1.0-0.deb11.9-amd64 (= 6.1.27-1~bpo11+1), which is not
installable.

As a consequence, DKMS modules are not built after an upgrade. Therefore
hardware devices depending on DKMS modules will not work anymore.

Steps to reproduce, starting with a fresh install of
debian-11.7.0-amd64-netinst.iso:

  * add the following APT source in /etc/apt/sources.list:
    deb http://deb.debian.org/debian bullseye-backports main contrib non-free"
  * apt update
  * apt install -t bullseye-backports linux-image-amd64
    -> ok: kernel 6.1 is successfully installed
  * apt install -r bullseye-backports linux-headers-amd64
    -> not ok: installation fails with the following message:

  Some packages could not be installed. This may mean that you have
  requested an impossible situation or if you are using the unstable
  distribution that some required packages have not yet been created
  or been moved out of Incoming.
  The following information may help to resolve the situation:
  
  The following packages have unmet dependencies:
   linux-headers-amd64 : Depends: linux-headers-6.1.0-0.deb11.9-amd64 (= 6.1.27-1~bpo11+1) but it is not installable
  E: Unable to correct problems, you have held broken packages.

I'm not totally sure it is actually a bug, please excuse me if I did something
wrong.

Regards,

LB.

-- System Information:
Debian Release: 11.7
  APT prefers oldstable-updates
  APT policy: (500, 'oldstable-updates'), (500, 'oldstable-security'), (500, 'oldstable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.10.0-25-amd64 (SMP w/2 CPU threads)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages linux-headers-amd64 depends on:
pn  linux-headers-5.10.0-22-amd64        <none>
pn  linux-headers-5.10.0-25-amd64        <none>
pn  linux-headers-6.1.0-0.deb11.9-amd64  <none>

linux-headers-amd64 recommends no packages.

linux-headers-amd64 suggests no packages.