title: Homebrew is generating two warnings
body: <p>I use Homebrew as the package manager.   I run this command:  </p>
  
  <pre><code>brew update
  </code></pre>
  
  <p>But I  got this error:</p>
  
  <blockquote>
    <p>error: unable to unlink old 'bin/brew' (Permission denied)</p>
    
    <p>Error: Failed while executing git pull <a href="http://github.com/mxcl/homebrew.git" rel="noreferrer">http://github.com/mxcl/homebrew.git</a> master</p>
  </blockquote>
  
  <p>Running again under sudo:</p>
  
  <blockquote>
    <p>/usr/local/Library/Homebrew/brew.h.rb:1: warning: already initialized constant FORMULA_META_FILES<br>
    /usr/local/Library/Homebrew/brew.h.rb:2: warning: already initialized constant PLEASE_REPORT_BUG
    error: The following untracked working tree files would be overwritten by checkout:</p>
    
    <p>.gitignore<br>
    ;;; big list goes here ;;;;</p>
  </blockquote>
  
  <p>And now, every brew command generates these warning:  </p>
  
  <blockquote>
    <p>/usr/local/Library/Homebrew/brew.h.rb:1: warning: already initialized constant FORMULA_META_FILES<br>
    /usr/local/Library/Homebrew/brew.h.rb:2: warning: already initialized constant PLEASE_REPORT_BUG</p>
  </blockquote>
  
  <p>Any idea what is going wrong?</p>