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

[Simon McVittie]

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).

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

     getent passwd messagebus
     getent group messagebus

>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.

>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?

     smcv