[gentoo-alt] [PREFIX] OS X launchd DISPLAY environment variable

[John Gibson]

I recently upgraded to 10.5 and had to rebootstrap.  After doing so,  
X11 apps installed to my prefix yielded errors like this:
Can't connect to display `/tmp/launch-ICEBGq/:0': Invalid argument at...

See here for some more info:
http://lists.apple.com/archives/x11-users/2008/Nov/msg00089.html

With xhost tweaking I got stuff to work by doing this:
DISPLAY=localhost:0.0.

I looked into the libX11 configure script and found this:
   --with-launchd          Build with support for Apple's launchd  
(default:
                           auto)

Apparently the auto detection didn't work.  I forced the switch on  
with a new USE flag (see the attached patch) and the launchd-specific  
DISPLAY variable worked.

Is the USE flag the right approach?  Can we default the switch to be  
on for macos?

John