my system is centos 5.5 i386. my repository is default. i installed and run revisor.
i got this fatal error:

Traceback (most recent call last):
File "/usr/lib/python2.4/site-packages/revisor/ready_screen.py", line 183, in button_forward_clicked
self.gui.displayBuildMedia()
File "/usr/lib/python2.4/site-packages/revisor/gui.py", line 278, in displayBuildMedia
self.BuildMedia.start()
File "/usr/lib/python2.4/site-packages/revisor/build_media.py", line 65, in start
self.base.lift_off()
File "/usr/lib/python2.4/site-packages/revisor/base.py", line 978, in lift_off
self.buildInstallationMedia()
File "/usr/lib/python2.4/site-packages/revisor/base.py", line 1157, in buildInstallationMedia
mypungi.doCreateRepo(database=database,callback=pungicallback)
File "/usr/lib/python2.4/site-packages/revisor/pungi.py", line 143, in doCreateRepo
comps = self.cfg.get_comps()
File "/usr/lib/python2.4/site-packages/revisor/cfg.py", line 234, in get_comps
groupfile = repo.getGroups()
File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1558, in getGroups
if 'group_gz' in self.repoXML.fileTypes():
File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1392, in
repoXML = property(fget=lambda self: self._getRepoXML(),
File "/usr/lib/python2.4/site-packages/yum/yumRepo.py", line 1388, in _getRepoXML
raise Errors.RepoError, msg

== yum.Errors.RepoError: Cannot retrieve repository metadata (repomd.xml) for repository: extras-source. Please verify its path and try again ==

when i look at extras-source repomd.xml i see http://linux.duke.edu/metadata/repo url
but this url does not contain required data.