Bug#470123: /usr/bin/users-admin: users-admin does not open

[Sam Morris]

Package: gnome-system-tools
Version: 2.20.0-1
Severity: serious
File: /usr/bin/users-admin

users-admin seems totally broken at the moment. It never shows its main
window; instead it prints:

Liboobs-WARNING **: There was an unknown error communicating with the
backends: Cannot do system-bus activation with no user

If run as root, it prints:

Liboobs-WARNING **: There was an unknown error communicating with the backends: Activation of org.freedesktop.SystemToolsBackends timed out
Liboobs-WARNING **: There was an unknown error communicating with the backends: Cannot do system-bus activation with no user

-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (530, 'testing'), (520, 'unstable'), (510, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.24-1-686 (SMP w/1 CPU core)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages gnome-system-tools depends on:
ii  gconf2                 2.20.1-3          GNOME configuration database syste
ii  gksu                   2.0.0-5           graphical frontend to su
ii  libatk1.0-0            1.20.0-1          The ATK accessibility toolkit
ii  libc6                  2.7-6             GNU C Library: Shared libraries
ii  libcairo2              1.4.14-1          The Cairo 2D vector graphics libra
ii  libdbus-1-3            1.1.2-1           simple interprocess messaging syst
ii  libfontconfig1         2.5.0-2           generic font configuration library
ii  libfreetype6           2.3.5-1+b1        FreeType 2 font engine, shared lib
ii  libgconf2-4            2.20.1-3          GNOME configuration database syste
ii  libglade2-0            1:2.6.2-1         library to load .glade files at ru
ii  libglib2.0-0           2.15.6-1          The GLib library of C routines
ii  libgnomevfs2-0         1:2.20.1-2        GNOME Virtual File System (runtime
ii  libgtk2.0-0            2.12.8-1          The GTK+ graphical user interface 
ii  libiw29                29-1              Wireless tools - library
ii  libnautilus-extension1 2.20.0-3          libraries for nautilus components 
ii  liboobs-1-3            2.20.0-1          GObject based interface to system-
ii  liborbit2              1:2.14.10-0.1     libraries for ORBit2 - a CORBA ORB
ii  libpango1.0-0          1.19.4-1          Layout and rendering of internatio
ii  libpng12-0             1.2.15~beta5-3    PNG library - runtime
ii  libx11-6               2:1.0.3-7         X11 client-side library
ii  libxml2                2.6.31.dfsg-1     GNOME XML library
ii  libxrender1            1:0.9.4-1         X Rendering Extension client libra
ii  perl                   5.8.8-12          Larry Wall's Practical Extraction 
ii  zlib1g                 1:1.2.3.3.dfsg-11 compression library - runtime

Versions of packages gnome-system-tools recommends:
ii  gnome-control-center          1:2.20.3-2 utilities to configure the GNOME d

-- no debconf information