As described in <https://lists.debian.org/debian-devel/2016/08/msg00554.html>
I'm trying to reduce how much dbus-launch is used in Debian.
gnome-session has code that explicitly runs dbus-launch if
DBUS_SESSION_BUS_ADDRESS isn't set.

The major D-Bus implementations (libdbus, GDBus, sd-bus) now have a
fallback code path, before trying X11 autolaunch, when
DBUS_SESSION_BUS_ADDRESS is unset: if XDG_RUNTIME_DIR is set, and
XDG_RUNTIME_DIR/bus exists, is a socket and is owned by the
process's uid, then they will use it. In particular, dbus-user-session
sets up that situation.

For the moment, dbus-user-session does make sure DBUS_SESSION_BUS_ADDRESS
is set, to be nice to packages that don't have this fallback path.
However, I'd like to avoid requiring that in future, by adapting
the dbus-launch code in gnome-session and its forks to look for
XDG_RUNTIME_DIR/bus before trying dbus-launch.

I'll open an upstream bug after doing this MBF.

Thanks,
    S

Hi Simon

Have you filed such a bugreport in the mean time?

Regards,
Michael

Control: forwarded 835887 https://bugzilla.gnome.org/show_bug.cgi?id=694472
on this MBF hasn't been my top priority :-)

Turns out I opened an upstream bug 3.5 years ago, with a patch (which
isn't 100% right, but should be reasonably straightforward to adapt if
someone wants to pick it up).
<https://bugzilla.gnome.org/show_bug.cgi?id=694472>

Things that need fixing in that patch before it can be applied:
<https://bugzilla.gnome.org/show_bug.cgi?id=694472#c8>

    S