title: Cygwin save package selections for later reinstall
body: <p>I was wondering if there is a way to save the current package selections for cygwin for a later reinstall or porting on a different system. </p>
  
  <p>It would be really great to:</p>
  
  <ul>
  <li>run a command to export a list of installed packages on an existing system</li>
  <li>pass the list to the installer on another system in a way such as <code>setup-x86_64.exe --list list.txt</code></li>
  </ul>
  
  <p>I don't think the setup has such a switch, so even any type of script or batch working in this direction would be just fine.</p>
  
  <p>Since the number of needed packages is very high, it should be unattended in order to consider it as a good solution!</p>
  
  <p><strong>What would be the best way to accomplish a quick reinstall like this?</strong></p>