ports/170381: x11/slim window manager gives dbus errors starting xfce4

[matt]

>Number:         170381
>Category:       ports
>Synopsis:       x11/slim window manager gives dbus errors starting xfce4
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-ports-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Aug 05 00:30:01 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     matt
>Release:        10-CURRENT
>Organization:
>Environment:
FreeBSD freebsd.local 10.0-CURRENT FreeBSD 10.0-CURRENT #1: Tue Jul 31 23:54:27 PDT 2012     root at freebsd.local:/usr/obj/usr/src/sys/V8  amd64

>Description:
Using slim login manager, from x11/slim, putting "exec startxfce4" "startxfce4" "ck-launch-session dbus-launch xfce4-session" etc would cause a "Failed to connect to settings server" with an error related to being refused by a DBUS socket. The name of the socket changes each boot. Also, xfdesktop was dropping core. This was not the case using gdm, xdm or simply startx. 

Gnome had similar errors, but xterm worked fine. To make matters more confusing, the above commands worked as expected when typed into the xterm.
>How-To-Repeat:
Install slim (with or without PAM)
Install xfce4 (& dbus hal xorg etc)
Start slim from /etc/ttys 
put "exec ck-launch-session dbus-launch xfce4-session" > .xinitrc
(or exec startxfce4 or whatever)
Login via slim
Dialog appears and no desktop is possible

>Fix:
Putting either
xterm -e 'startxfce4'
or
csh -c 'startxfce4'
works fine, which I cannot explain.


>Release-Note:
>Audit-Trail:
>Unformatted: