title: how to use appcfg.py for google-app-engine projects created using google's eclipse plugin?
body: <p>I have created a google-app-engine java project in Eclipse using Google's Eclipse plugin. My previous attempt to deploy failed. Now, when I retry, I get the following message:</p>
  
  <p>Unable to update app: Error posting to URL : <a href="http://appengine.google.com/api/appversion/create?app_id=mybdaywisherversion=1" rel="noreferrer">http://appengine.google.com/api/appversion/create?app_id=mybdaywisherversion=1</a> 
  409 conflict
  Another transaction for this user is already in progress for this app and major version. That user can undo the transaction with appcfg.py's "rollback" command.</p>
  
  <p>Now, I have always used the google-app-engine features from inside Eclipse only and have not a clue how to run the appcfg.py command.</p>
  
  <p>Could not get much help from documentation available over the internet. The only thing I could make out was for mac (I'm on mac), the command to be used is appcfg.sh. Inside Eclipse, I looked where App-Engine SDK is located on my machine and went to that location.
  Even found appcfg.sh there. But when I try to run it, it only reports the error "command not found". Tried various alternatives to run it (like tried running it with sudo, tried running it as ./appcfg.sh by going to whether its located) but no success</p>
  
  <p>Can someone please tell me the step I will have to follow to run the apcfg command?</p>