title: Homebrew error occurred when I command "brew cask install virtualbox" or "brew cask search google-chrome"
body: <p>I'm trying to install virtual box with brew-cask, but That returns this kind of error and I cannot install virtualbox. I use MacOSX Lion 10.7.5 and homebrew 0.9.5, ruby 2.1.0-p0</p>
  
  <p>I've described the process in Terminal below.</p>
  
  <p>First of all, <code>brew tap</code> command is succeeded.</p>
  
  <pre><code>    $ brew tap phinze/cask
      Cloning into '/usr/local/Library/Taps/phinze/homebrew-cask'...
      remote: Reusing existing pack: 32538, done.
      remote: Counting objects: 36, done.
      remote: Compressing objects: 100% (36/36), done.
      remote: Total 32574 (delta 16), reused 2 (delta 0)
      Receiving objects: 100% (32574/32574), 11.72 MiB | 379 KiB/s, done.
      Resolving deltas: 100% (19138/19138), done.
      Tapped 1 formula
      It looks like you tapped a private repository. To avoid entering your
      credentials each time you update, you can use git HTTP credential caching
      or issue the following command:
  
        cd /usr/local/Library/Taps/phinze/homebrew-cask
        git remote set-url origin git@github.com:phinze/homebrew-cask.git
  </code></pre>
  
  <p>Second, I've already installed brew-cask as below</p>
  
  <pre><code>    $ brew install brew-cask
      Warning: brew-cask-0.35.0 already installed
  </code></pre>
  
  <p>Third, when I tried to install virtualbox, but it returns this kind of error, and I cannot get install the Virtualbox.</p>
  
  <pre><code>    $ brew cask install virtualbox
      ==&gt; Removing legacy Tap
      Error: No available cask for virtualbox
  </code></pre>