title: Pip freeze gives me this error related with git
body: <p>I am working with python and git on a simple Turbogears2 project that I've built just for fun. In a certain moment I want to deploy it to Heroku, so I do the usual <code>pip freeze &gt; requirements.txt</code> and I get this error:</p>
  
  <pre><code>Error when trying to get requirement for VCS system Command /usr/bin/git config
  remote.origin.url failed with error code 1 in /home/ricardo/myprojs/hellotg22/example,
  falling back to uneditable format
  </code></pre>
  
  <p>And in the <code>requirements.txt</code> that it produces, listed between all the dependencies, I find this line, whi doesn't look good at all:</p>
  
  <pre><code>...
  decorator==3.4.0
  ## !! Could not determine repository location
  example==0.1dev
  ...
  </code></pre>
  
  <p>Does any body know what the problem is?</p>
  
  <p>Anyway, I have managed to obtain the requirements.txt file, but I would like to know what is going on with that error.</p>