[TriLUG] CentOS Yum question

[Roy Vestal]

I'm trying to build a live CentOS4.3 livecd. I'm following the 
directions from: http://www.byteclub.net/wiki/CentOS_Live .
I'm told to copy my yum.conf to my livecd dir and the run yum
-c /path/to/yum.conf --installroot=/path install pkgs. When I
do this, i get "Null is not a valid release..." error. If I
run yum install pkgs it works fine. just when I do
--installroot= to alter the path to install. ideas?