Darcs fails to build in koji on ppc64 because there is no existing ghc package for ppc64. To keep darcs up to date for the other platforms requires adding an ExcludeArch: ppc64 to the spec.
Changing version to '9' as part of upcoming Fedora 9 GA. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping