mitchellh/packer — pull request #473 by pearkes (2013-09-29 09:04:41+00:00)
Title: builder/digitalocean: error message key is "message" not "error_message"

Don't know if this was a recent API change, but the assertion was causing a panic (`type nil not string`) on bad responses for DO. Changing the API error response to the proper key "error" fixes this.