Надо заменить perl на ruby в %description
rpm-build-ruby-1:0.1.0-alt0.1 -> sisyphus: * Mon Jun 29 2009 Alexey I. Froloff <raorn@altlinux> 1:0.1.0-alt0.1 - Updated for ruby 1.9 - Fixed typo in description (closes: #20624) - Stop processing on syntax error