It use rails 3.0 v .but when I try to generate scaffold it perform me Could not find gem 'mysql2 (>= 0, runtime)' in any of the gem sources. Try running `bundle install`. I already tried but It's error and show bunch of massage Using rake (0.8.7) /usr/local/lib/site_ruby/1.8/rubygems/remote_fetcher.rb:180:in `fetch_path': SocketError: getaddrinfo: Name or service not known (http://rubygems.org/quick/Marshal.4.8/abstract-1.0.0.gemspec.rz) (Gem::RemoteFetcher::FetchError) from /usr/local/lib/site_ruby/1.8/rubygems/spec_fetcher.rb:106:in `fetch_spec' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/remote_specification.rb:47:in `_remote_specification' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/remote_specification.rb:25:in `fetch_platform' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/source.rb:247:in `download_gem_from_uri' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/source.rb:76:in `fetch' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/installer.rb:45:in `run' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/spec_set.rb:12:in `each' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/spec_set.rb:12:in `each' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/installer.rb:44:in `run' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/installer.rb:8:in `install' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/cli.rb:217:in `install' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor/task.rb:22:in `send' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor/task.rb:22:in `run' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor/invocation.rb:118:in `invoke_task' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor.rb:246:in `dispatch' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/lib/bundler/vendor/thor/base.rb:389:in `start' from /usr/lib/ruby/gems/1.8/gems/bundler-1.0.0/bin/bundle:13 from /usr/bin/bundle:19:in `load' from /usr/bin/bundle:19 What ' s wrong and what should I do Very thanks again