---> Package gnutls.x86_64 0:2.8.5-10.el6 will be updated
---> Package gnutls.x86_64 0:2.8.5-10.el6_4.2 will be an update
---> Package opennebula-ruby.x86_64 0:4.2.0-1 will be installed
--> Processing Dependency: rubygem-uuidtools for package: opennebula-ruby-4.2.0-1.x86_64
--> Processing Dependency: rubygem-thin for package: opennebula-ruby-4.2.0-1.x86_64
--> Processing Dependency: rubygem-sqlite3-ruby for package: opennebula-ruby-4.2.0-1.x86_64
--> Processing Dependency: rubygem-sinatra for package: opennebula-ruby-4.2.0-1.x86_64
--> Processing Dependency: rubygem-sequel for package: opennebula-ruby-4.2.0-1.x86_64
--> Processing Dependency: rubygem-rack for package: opennebula-ruby-4.2.0-1.x86_64
--> Processing Dependency: rubygem-nokogiri for package: opennebula-ruby-4.2.0-1.x86_64
--> Processing Dependency: rubygem-json for package: opennebula-ruby-4.2.0-1.x86_64
--> Finished Dependency Resolution
Error: Package: opennebula-ruby-4.2.0-1.x86_64 (opennebula)
           Requires: rubygem-sequel
Error: Package: opennebula-ruby-4.2.0-1.x86_64 (opennebula)
           Requires: rubygem-sqlite3-ruby
Error: Package: opennebula-ruby-4.2.0-1.x86_64 (opennebula)
           Requires: rubygem-json
Error: Package: opennebula-ruby-4.2.0-1.x86_64 (opennebula)
           Requires: rubygem-nokogiri
Error: Package: opennebula-ruby-4.2.0-1.x86_64 (opennebula)
           Requires: rubygem-sinatra
Error: Package: opennebula-ruby-4.2.0-1.x86_64 (opennebula)
           Requires: rubygem-rack
Error: Package: opennebula-ruby-4.2.0-1.x86_64 (opennebula)
           Requires: rubygem-uuidtools
Error: Package: opennebula-ruby-4.2.0-1.x86_64 (opennebula)
           Requires: rubygem-thin

########################################################################################

[root@opennebula ~]# rpm -qa | grep ruby
ruby-libs-1.8.7.352-12.el6_4.x86_64
ruby-irb-1.8.7.352-12.el6_4.x86_64
rubygem-flexmock-0.8.6-1.1.el6.noarch
rubygem-flexmock-doc-0.8.6-1.1.el6.noarch
ruby-devel-1.8.7.352-12.el6_4.x86_64
ruby-1.8.7.352-12.el6_4.x86_64
ruby-rdoc-1.8.7.352-12.el6_4.x86_64
rubygems-1.3.7-1.el6.noarch
rubygem-rake-0.8.7-2.1.el6.noarch

###########################################################################

[root@opennebula ~]# cat /etc/yum.repos.d/opennebula.repo
[opennebula]
name=opennebula
baseurl=http://opennebula.org/repo/CentOS/6/stable/$basearch
enabled=1
gpgcheck=0