我不确定为什么这不起作用。请参阅以下内容。我试图命令rails s并且服务器没有启动并给了我一些我不理解的错误！
Muhammeds-MacBook-Pro:simple_cms muhammedz786$ rails s
/Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/mysql2-0.3.14/lib/mysql2.rb:8:in `require': dlopen(/Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/extensions/x86_64-darwin-13/2.1.0-static/mysql2-0.3.14/mysql2/mysql2.bundle, 9): Library not loaded: libmysqlclient.18.dylib (LoadError)
Referenced from: /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/extensions/x86_64-darwin-13/2.1.0-static/mysql2-0.3.14/mysql2/mysql2.bundle
Reason: image not found - /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/extensions/x86_64-darwin-13/2.1.0-static/mysql2-0.3.14/mysql2/mysql2.bundle
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/mysql2-0.3.14/lib/mysql2.rb:8:in `<top (required)>'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.5.1/lib/bundler/runtime.rb:76:in `require'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.5.1/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.5.1/lib/bundler/runtime.rb:72:in `each'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.5.1/lib/bundler/runtime.rb:72:in `block in require'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.5.1/lib/bundler/runtime.rb:61:in `each'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.5.1/lib/bundler/runtime.rb:61:in `require'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.5.1/lib/bundler.rb:131:in `require'
from /Users/muhammedz786/rails_application/simple_cms/config/application.rb:7:in `<top (required)>'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `require'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:74:in `block in <top (required)>'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `tap'
from /Users/muhammedz786/.rbenv/versions/2.1.0/lib/ruby/gems/2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'
Muhammeds-MacBook-Pro:simple_cms muhammedz786$