crowbar/barclamp-crowbar — pull request #407 by aspiers (2013-02-26 20:01:30+00:00)
Title: change uses of throw to raise

'throw' is for escaping from control flow, whereas 'raise' is for
error conditions, e.g.

http://rubylearning.com/blog/2011/07/12/throw-catch-raise-rescue-im-so-confused/