[Samba] samba-ad-dc from debian backports fails to start with /usr/sbin/samba missing

[Paul Leiber]

Dear Samba list,

I have a Samba instance running as an ad-dc on debian bullseye. Some 
time ago, I changed the standard installation to backports with

apt -t bullseye-backports install samba

After a recent update, samba-ad-dc service didn't start anymore. The 
journal gave the following hint:

Jul 04 20:05:37 xxx (samba)[5864]: samba-ad-dc.service: Failed at step 
EXEC spawning /usr/sbin/samba: No such file or directory

Indeed, the file was not there.

Uninstalling samba (including some dependencies which needed to be 
uninstalled manually) and installing the non-backports version restored 
functionality.

Do you have an idea what could be the cause for this?

Thank you in advance,

Paul