coderanger/raven-ruby — pull request #1 by myronmarston (2012-10-05 20:14:36+00:00)
Title: Don't subclass `Exception`.

Most errors should subclass `StandardError`. A bare rescue will not
catch `Exception`-subclassed errors; that's be design because `Exception`-subclassed errors are intended for situations like signals (e.g. when
a user halts a script with "ctrl-c") or fatal situations like
out-of-memory.

See http://www.codeotaku.com/blog/2009-08/ruby-standard-error/index for
more info on the design of Ruby's exception hierarchy.