install_package "yaml-0.1.4" "http://pyyaml.org/download/libyaml/yaml-0.1.4.tar.gz#36c852831d02cf90508c29852361d01b"
install_package "ruby-1.9.3-p385" "http://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p385.tar.gz#3e0d7f8512400c1a6732327728a56f1d"