title: How to use hg convert properly
body: <p>at one point I committed large files to my hg repository, I later did a <code>hg forget</code> on these files, but now my repository is quite big and on every new clone it takes ages as these files are still being pulled down as part of the history.</p>
  
  <p>I am using this <a href="https://stackoverflow.com/questions/10103227/how-do-you-remove-big-files-from-history-in-mercurial">SO post</a> to try and <code>convert</code> my repository into a repository that doesn't know of the large files. I am doing the following</p>
  
  <p>assume my repository has the following structure:</p>
  
  <pre><code>~/workspace/
      project/
          data/
              large_file.txt
          src/
              ...
  </code></pre>
  
  <p>I am doing the following</p>
  
  <pre><code>cd workspace/project
  echo data/large_file.txt &gt;&gt; /tmp/myfilemap
  hg convert --filemap ~/workspace/project ~/workspace/new_repo
  </code></pre>
  
  <p>However the <code>new_repo</code> just appears to be empty.</p>
  
  <p>Am I doing something wrong?</p>