After going through depcheck details with John, I think that using createrepo for making repoinfo for depcheck is not the right way to do things. My main concern is with multilib - not all 32bit rpms are included in x86_64 and there's no real way to determine which are supposed to be included without inspecting the filelists for each rpm. When used with the proper configuration, mash does this checking and properly creates the multilib repos.

Create a directive to run mash on a directory with the following args:
* rpmdir - the directory containing rpms to mash
* repodir - the base directory into which output should be placed
* configfile - path to config file to be used during mash
* dodelta - create drpms during mash (default FALSE)