执行 rake assets:precompile Could not load SystemTimer >= v1.2.0. Falling back to timeout.rb. SystemTimer is STRONGLY recommended for timeouts in Ruby 1.8.7. See http://ph7spot.com/blog/system-timer-1-2-release for details. WARNING: using the built-in Timeout class which is known to have issues when used for opening connections. Install the SystemTimer gem if you want to make sure the Redis client will not hang. /home/administrator/ruby-china/vendor/cache/ruby/1.8/bundler/gems/bootstrap-rails-7fe2d48ef0b0/lib/bootstrap-rails/version.rb:3: warning: already initialized constant VERSION rake aborted! uninitialized constant YAML::ENGINE