[Pkg-utopia-maintainers] Bug#1099534: dbus-system-bus-common: Fails to install when messagebus user already exists

[John Paul Adrian Glaubitz]

Hello,

On Tue, 2025-03-04 at 15:52 +0000, Simon McVittie wrote:
> Control: tags -1 + moreinfo
> 
> On Tue, 04 Mar 2025 at 16:35:45 +0100, John Paul Adrian Glaubitz wrote:
> > the package dbus-system-bus-common fails to install when the messagebus user already
> > exists which seems to be the case on some systems:
> 
> Specifically, it looks as though on the affected system, the messagebus
> user exists outside the Debian-Policy-defined system user range 100-999
> (or possibly adduser is misidentifying it as being outside that range).

This is inside a schroot on a buildd and it looks like something recently
changed, either with the dbus package or any other package.

> Please provide details of the messagebus user/group? This should do it:
> 
>      getent passwd messagebus
>      getent group messagebus

(sid-alpha-sbuild)root at alpha-sc-03:/# getent passwd messagebus
messagebus:x:104:111::/nonexistent:/usr/sbin/nologin
(sid-alpha-sbuild)root at alpha-sc-03:/# getent group messagebus
messagebus:x:111:
(sid-alpha-sbuild)root at alpha-sc-03:/# 

> > Setting up dbus-system-bus-common (1.16.2-1) ...
> > fatal: The user `messagebus' already exists, but is not a system user. Exiting.
> > dpkg: error processing package dbus-system-bus-common (--configure):
> > installed dbus-system-bus-common package post-installation script subprocess returned error exit status 13
> > Setting up sbuild-build-depends-dose3-dummy (0.invalid.0) ...
> > dpkg: dependency problems prevent configuration of dbus:
> > dbus depends on dbus-system-bus-common (>= 1.16.2-1); however:
> >  Package dbus-system-bus-common is not configured yet.
> 
>  From the mention of sbuild-build-depends-dose3-dummy, I assume this is a
> sbuild chroot, in which case /etc/passwd and /etc/group were probably
> copied from the host system by sbuild. If so, running the commands above
> on the host system is probably sufficient.

Correct. This is on a buildd.

See: https://buildd.debian.org/status/fetch.php?pkg=altos&arch=alpha&ver=1.9.19-4&stamp=1741107746&raw=0

> > The postinst script should probably check for the existance of the messagebus account
> > instead of trying to create it unconditionally.
> 
> If I understand correctly, the adduser maintainers' recommendation is
> that, to the contrary, packages *should* invoke adduser unconditionally,
> and let adduser decide what (if anything) it needs to do to arrange for
> the desired state to exist. adduser maintainers: is that correct, or
> am I misunderstanding?

No idea. I'm just reporting a recent regression that affects multiple buildds and causes
the installation of build dependencies to fail. Currently, it affects alpha, powerpc, ppc64
and sh4.

See: https://buildd.debian.org/status/package.php?p=altos&suite=sid

Look at number of attempted builds in the "logs" column.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
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