alphagov/vcloud-walker — pull request #57 by annashipman (2014-02-07 16:27:35+00:00)
Title: [#62889568] Nothing in bin should rely on bundler

This is probably why the gem isn't working - the 'bundler/setup' will configure a gemset based on the Gemfile found in whatever directory you happen to be in when you call it. If that Gemfile doesn't include vcloud-walker, then the later require won't find anything.