dbus-launch terminated abnormally with the following error: No protocol specified

Question

After a recent upgrade in my Arch Linux x64 system, I keep getting this warning message after installing or removing packages with pacman.

(gconftool-2:5207): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
/usr/bin/dbus-launch terminated abnormally with the following error: No protocol specified
Autolaunch error: X11 initialization failed.

So, far I have not seen any ill effects from this (that I know of), but I would like to make this warning go away.

EDIT

I can consistently reproduce this by installing or uninstalling GNOME Do. Both of the following commands result in the output above.

$ sudo pacman -S gnome-do
$ sudo pacman -Rns gnome-do

Running xhost + seems to temporarily alleviate the warning (at least until I reboot). I can run xhost - and the warning returns.

UPDATE This problem went away after a few upgrades (i.e. pacman -Syu).

Solution

Try:

export $(dbus-launch)

and then try any dbus based commands.

Comments

[slm]

Are you using XFCE? I found this thread: code.google.com/p/acpi-eeepc-generic/issues/detail?id=47

[CoOl]

As far as I understand what's going on, it's your display manager init script (such as xdm or gdm3) is trying to start X, creates a per-user instance of D-Bus and for some reason GConf fails to connect to its socket. A common reason for such a problem might be just in that your per-user instance of D-bus is started with wrong permissions, it must run under your UID (see askubuntu.com/questions/135573/… and bbs.archlinux.org/viewtopic.php?id=151914). Try ps -axfl and look into UIDs and arguments of your processes.

[Stark07]

It initializes the dbus-daemon. Ideally that command is executed within a user's login script. More details here