[Pkg-utopia-maintainers] Bug#495257: dbus: System bus must not be restarted during package upgrades

[Sam Morris]

Package: dbus
Version: 1.2.1-3
Severity: serious

Yesterday I upgraded my system and during the process the system dbus
daemon was restarted. This caused a variety of interesting and amusing
things to happen to my system, including gnome-power-manager dieing,
network-manager dieing, the gnome panel dieing, and rhythmbox freezing
up and chewing 100% of the CPU.

The bugs I filed upstream are:

http://bugzilla.gnome.org/show_bug.cgi?id=547932
http://bugzilla.gnome.org/show_bug.cgi?id=547850
http://bugzilla.gnome.org/show_bug.cgi?id=547851
http://bugzilla.gnome.org/show_bug.cgi?id=547849

In the last of these, the NetworkManager developers were quite clear
that distributions must *not* restart the dbus system bus, ever:

"Distros should not be restarting the bus on upgrade of the dbus package.  NM
supports bus reconnections when it's been kicked off because of doing something
bad, but does not support bus reconnections if dbus itself goes away."

and

"the user wouldn't need to scratch his/her head if the distro did not restart
the dbus service on a package upgrade.  the bus is _not_ meant to be restarted
on-the-fly.  this is also the view of upstream dbus maintainers and has always
been the view of upstream dbus maintainers.  there are way too many pieces here
on the bus that NM talks to, and the code for doing state resynchronization
after a bus restart would be hugely prohibitive when the bus should just not be
restarted in the first place."

A dbus developer also cited a mailing list thread
<http://mail.gnome.org/archives/networkmanager-list/2005-March/msg00022.html>
where it was stated,

"I don't think we should really try to support this.  Restarting D-BUS
should be viewed like trying to live-restart a new kernel.  There's so
many complicated issues in it, and it'll be a rarely-tested code path.
Right now it's a bug that the Fedora D-BUS and NetworkManager RPM
scripts restart after a package upgrade."

Given the amount of crashes, freezes and general random weird behaviour
that occurs when the system dbus daemon is restarted, it is clear that
dbus clients simply can not handle the daemon being restarted. Since the
upstreams of both dbus clients, and of dbus itself, say that this should
not be done, and are not interested in accepting patches to make things
work, we really shouldn't be doing it.

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

Kernel: Linux 2.6.26-1-686 (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 dbus depends on:
ii  adduser                       3.108      add and remove users and groups
ii  debianutils                   2.30       Miscellaneous utilities specific t
ii  libc6                         2.7-13     GNU C Library: Shared libraries
ii  libdbus-1-3                   1.2.1-3    simple interprocess messaging syst
ii  libexpat1                     2.0.1-4    XML parsing C library - runtime li
ii  libselinux1                   2.0.65-2   SELinux shared libraries
ii  lsb-base                      3.2-19     Linux Standard Base 3.2 init scrip

Versions of packages dbus recommends:
ii  dbus-x11                      1.2.1-3    simple interprocess messaging syst

dbus suggests no packages.

-- no debconf information