Comment 1 for bug 1049537

The error is seen because

1) the code does not download the jenkins stuff if it exists, and next would fail when the mismatch in the length occurs. You can add checks for an existing jenkins.war to make sure we have something new available and remove if it true and download the latest, like that the command wont fail

2) OR if the jenkins URL used to download the war file is not reachable.