install_package "yaml-0.1.5" "http://pyyaml.org/download/libyaml/yaml-0.1.5.tar.gz#24f6093c1e840ca5df2eb09291a1dbf1" --if needs_yaml
install_package "openssl-1.0.1e" "https://www.openssl.org/source/openssl-1.0.1e.tar.gz#66bf6f10f060d561929de96f9dfe5b8c" mac_openssl --if has_broken_mac_openssl
install_package "ruby-2.1.0" "http://cache.ruby-lang.org/pub/ruby/2.1/ruby-2.1.0.tar.gz#9e6386d53f5200a3e7069107405b93f7" ldflags_dirs standard verify_openssl