Rubyonrails Rails：您已经激活了 rake 10.3.1，但您的 Gemfile 需要 rake 10.2.2 (Gem：：LoadError)

以下是我的错误:

rake aborted!
Gem::LoadError: You have already activated rake 10.3.1, but your Gemfile requires rake 10.2.2. Prepending `bundle exec` to your command may solve this.
/Users/AaronWilliamson/.gem/ruby/2.1.0/gems/bundler-1.5.3/lib/bundler/runtime.rb:34:in `block in setup'
/Users/AaronWilliamson/.gem/ruby/2.1.0/gems/bundler-1.5.3/lib/bundler/runtime.rb:19:in `setup'
/Users/AaronWilliamson/.gem/ruby/2.1.0/gems/bundler-1.5.3/lib/bundler.rb:119:in `setup'
/Users/AaronWilliamson/.gem/ruby/2.1.0/gems/bundler-1.5.3/lib/bundler/setup.rb:7:in `<top (required)>'
/Users/AaronWilliamson/Desktop/Ripelist-Classifieds/config/boot.rb:4:in `<top (required)>'
/Users/AaronWilliamson/Desktop/Ripelist-Classifieds/config/application.rb:1:in `<top (required)>'
/Users/AaronWilliamson/Desktop/Ripelist-Classifieds/Rakefile:4:in `<top (required)>'
LoadError: cannot load such file -- bundler/setup
/Users/AaronWilliamson/Desktop/Ripelist-Classifieds/config/boot.rb:4:in `<top (required)>'
/Users/AaronWilliamson/Desktop/Ripelist-Classifieds/config/application.rb:1:in `<top (required)>'
/Users/AaronWilliamson/Desktop/Ripelist-Classifieds/Rakefile:4:in `<top (required)>'
(See full trace by running task with --trace)

我不能运行任何rake任务，这似乎是我所有其他问题的根源.几天前我运行rake命令时不是这样的.有人能解释一下这里发生了什么，以及如何让我的应用回到正轨吗？我撞到墙了.而且，bundle exec并不能从根本上解决我的问题.我过go 从来没有这样做过，现在仍然不起作用.