title: unable to evaluate symlinks in Dockerfile
body: <p>When I input</p>
  
  <p><code>docker build -t tutum/apache-php .
  </code></p>
  
  <p>in docker, it will output the error</p>
  
  <p><code>unable to prepare context: unable to evaluate symlinks in Dockerfile path: GetFileAttributesEx C:\User\gao\Dockerfile: The system cannot find the file specified.
  </code></p>
  
  <p>What does this mean? Any advice is helpful. Thank you.</p>