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

[Paul Leiber]

Am 05.07.2024 um 07:55 schrieb Michael Tokarev:
> 04.07.2024 21:27, Paul Leiber via samba wrote:
>> 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
> 
> Paul, others who also hit this issue.  I'm curious, I really am, - why 
> aren't you seeing the
> NEWS entries I've written.
> 
> Debian packages has NEWS mechanism - important information which is 
> supposed to be presented
> to the user on package upgrades.  apt-listchanges package is responsible 
> for this -- it is
> a part of standard install, with Priority: standard, so it is initially 
> present on any
> debian system installed the regular way.  By default, NEWS entries, if 
> any, are displayed
> while upgrading a package, apt waits the user to acknowledge the reading.
> 
> What prevents you and others from seeing these entries?

Hi Michael,

I am afraid I can't give you a definite answer to your question why I 
didn't see the NEWS entry.

I am a hobby user. I have a dozen or so headless Debian VMs running in 
my home network. Because the time to do the repetitive work of 
installing updates for each VM became quite significant, I am using 
unattended-upgrades package to automate installing updates. After having 
been bitten by some updates, ending up with non-functional VMs in some 
rare cases, I limited the unattended upgrades to debian-security, and 
this setup has been working generally fine for quite some time.

Unattended-upgrades sends e-mails from each VM after it has been doing 
something. I am not quite sure if NEWS entries would be shown in such an 
e-mail, but I am guessing that this is the case, as it is recommended to 
install apt-listchanges together with unattended-upgrades. I recently 
deleted my e-mail trashcan, so I can't check my e-mails for these NEWS 
entries. I will definitely pay attention in the future.

As the number of system e-mails with information on installed updated is 
quite high, I tend to just check which updates have been installed (in 
the first couple of lines in the e-mail) and skip the rest of the mail 
with dpkg logs and other information. So it could very well be that the 
NEWS entries have been sent to me via e-mail, and I didn't read the 
whole mail and thus didn't see the NEWS entry.

If the NEWS entry had been part of the automated e-mail from 
unattended-upgrades, it could have helped to add a Warning or something 
in the e-mail header and/or the first lines to check for NEWS entries, 
that would have increased the likelihood of me noticing it.

On top of that, I tend to watch the Samba mailing list, although I don't 
read every thread. The ones from you, Michael, I usually read, so it is 
quite likely that I have read your caveat on the upcoming changes, but I 
wasn't aware of that when sending my question to the list. Probably I 
simply forgot that fact. I did an internet search on my issue including 
the error message. I didn't find anything useful. This seems to 
corroborate my impression that mailing list content (also from other 
mailing lists, not only Samba) doesn't seem to be indexed/referenced 
very well by the google search engine.

I also guess that my case is similar to the one from Matthias Kühne in 
this thread, and I installed the update, but didn't restart the VM, so I 
didn't notice the change right away. I think that my last reboot before 
samba didn't work anymore had been a while ago. I checked dpkg and 
unattended-upgrades logs, but didn't find anything helpful.

Hope this helps a bit.

Thank you (and the whole Samba team, of course) for your work!

Paul