Description of problem: Please branch for EPEL5 so revisor-delta is usable. https://bugzilla.redhat.com/show_bug.cgi?id=425830
Awaiting popt inclusion into EPEL so deltarpm can be built. https://bugzilla.redhat.com/show_bug.cgi?id=427328
Didn't realize popt is already in RHEL, but with a different BuildRequires. Fixed deltarpm.spec and deltarpm has been built for both EL-4 and EL-5.