Build and Update the Yum Repository
From MediaWiki
Before building the ISO release image, you should make sure the NST yum repository is up to date and built for a ISO release.
The following will prune any old package builds and delta RPMs out of your repository and make sure the configuration files in the nst-release package are updated (these are the files that end up under the /etc/nst/iso/ directory). This can be done using the following command:
***Note: Do this on both 32/64 bit development environments
[root@nst-dev-32 repo]# make release-repo-build
***Note: This is new starting with the NST 18 and will need to be tested.