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.
You can also prime the pump by copying your development cache area to your new repository build area. This is optional, but saves download time and avoids the case of a server being down or an author upgrading a package since your last testing cycle.
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:
[nst@nst-repo repo]$ svn update # To make sure you are in sync with your manifest commit [nst@nst-repo repo]$ cp -r ../dev/yum/cache yum/ [nst@nst-repo repo]$ make release-repo-build