Description of problem: If I do redhat-config-packages --isodir=<dir_where_iso_images_are> then the rpms are found and can be installed. However, if I do redhat-config-packages --tree=<...> then I get a message "The path <...> does not look like a valid installation source." I have built a tree where I copied all of the files from the iso images. I have then used this tree to perform installs. I have tried pointing --tree= to that path that I use for NFS installs, to the RedHat direcotry under it and to the RedHat/RPMS directory ... nothing works. BTW, this tree was nfs mounted on the Fedora system.
OK, I found the problem ... I was missing the .discinfo file. I am going to leave this open because I believe that if the error message had been a bit clearer (saying that the .discinfo file was missing), the "problem" could have been easier to solve. The description of building the tree in the README file does not mention the .discinfo file. Furthermore, the .discinfo file does not appear to be needed by anaconda to do an install from the tree.
Updated readme