undefined method `relative_url_root' error

Hi,

To clear the error ,make the followning change,

changed line no. 51 in asset_packager/lib/synthesis/asset_packager_helper.rb

err line: source = "#{ActionController::Base.asset_host}#{@controller.request.relative_url_root}#{source}"

changed_to :
source = "#{ActionController::Base.asset_host}#{ActionController::Base.relative_url_root}#{source}"