title: Can't start a new Rails project
body: <p>I am trying to start a new Rails project but I am getting a really strange error. When I do:</p>
  
  <pre><code>rails new my_project 
  </code></pre>
  
  <p>I get a error:</p>
  
  <pre><code>/usr/local/Cellar/ruby/1.9.3-p125/lib/ruby/1.9.1/rubygems.rb:314:in `bin_path': can't find gem rails (["&gt;= 0"]) with executable rails (Gem::GemNotFoundException)
      from /usr/bin/rails:19:in `&lt;main&gt;'
  </code></pre>
  
  <p>What should I do to start a new project ?</p>