Quoting haml's warning: -------------------------------------- Haml 4.0 has many improvements, but also has changes that may break your application: * Support for Ruby 1.8.6 dropped * Support for Rails 2 dropped * Sass filter now always outputs <style> tags * Data attributes are now hyphenated, not underscored * html2haml utility moved to the html2haml gem * Textile and Maruku filters moved to the haml-contrib gem For more info see: http://rubydoc.info/github/haml/haml/file/CHANGELOG.md -------------------------------------- So, upgrading to v4, if we want to still have the html2haml utility we should package an extra gem. That would also be a good opportunity to update haml-rails as well. I packaged the new version and didn't encounter any real issues, so this should be a fairly easy update. Working spec : http://axilleas.fedorapeople.org/pkgs/rubygem-haml/rubygem-haml.spec Koji build : http://koji.fedoraproject.org/koji/taskinfo?taskID=5899597