Today, Amazon updated their Amazon linux AMI to "Amazon Linux 2015.03"
This caused yum-dump.py to have all sorts of problems when trying to resolve packages for use by the yum_package resource due to an upgrade of the python interpreter to version 2.7
You can find a workaround for the issue here https://forums.aws.amazon.com/thread.jspa?threadID=174341
Chef is tracking the issue here
The gist of the issue is that python was upgraded on the new AMI to version 2.7, but yum-dump.py only works with 2.6. It fails with a message like "ImportError: No Module named yum"