install_package "yaml-0.1.6" "http://pyyaml.org/download/libyaml/yaml-0.1.6.tar.gz#7da6971b4bd08a986dd2a61353bc422362bd0edcc67d7ebaac68c95f74182749" --if needs_yaml
install_package "openssl-1.0.1m" "https://www.openssl.org/source/openssl-1.0.1m.tar.gz#095f0b7b09116c0c5526422088058dc7e6e000aa14d22acca6a4e2babcdfef74" mac_openssl --if has_broken_mac_openssl
install_package "ruby-2.0.0-rc2" "http://cache.ruby-lang.org/pub/ruby/2.0/ruby-2.0.0-rc2.tar.gz#87072ab3e6d393d47f7402682364e4f24efe1c518969795cc01fcdeeb0e646f3" standard verify_openssl