title: Why do I get "Error: Errno::ENOENT: No such file or directory", but the file exists?
body: <p>I am using Carrierwave to upload a file. I am trying to read from the file in Rails and any method I use to try to open it returns an error.</p>
  
  <p>It returns <code>false</code> if I use:</p>
  
  <pre><code>File.exists(file_url)
  </code></pre>
  
  <p>If I try to use:</p>
  
  <pre><code>File.open(file_url, 'r'), 
  </code></pre>
  
  <p>I get the error:</p>
  
  <pre><code>Errno::ENOENT: No such file or directory - /uploads/document/file/2/doc-sample-file.txt
  from (irb):5:in `initialize'
  from (irb):5:in `open'
  from (irb):5
  from /Users/xxx/.rvm/gems/ruby-2.0.0-p0/gems/railties-3.2.13/lib/rails/commands/console.rb:47:in `start'
  from /Users/xxx/.rvm/gems/ruby-2.0.0-p0/gems/railties-3.2.13/lib/rails/commands/console.rb:8:in `start'
  from /Users/xxx/.rvm/gems/ruby-2.0.0-p0/gems/railties-3.2.13/lib/rails/commands.rb:41:in `&lt;top (required)&gt;'
  from script/rails:6:in `require'
  from script/rails:6:in `&lt;main&gt;'
  </code></pre>
  
  <p>If I try to load a file that has been uploaded to Carrierwave in the view, like an image, there is no issue. I can also visit the file path in the browser, but the methods cannot find the path.</p>