I'm not sure exactly which component is right here.
stacks.yaml is now on this location:
https://github.com/jboss-developer/jboss-stacks/blob/1.0.0.Final/stacks.yaml
It's no longer jdf, but jboss-developer. The old url still works through redirects, but it's probably a good idea to use the new one.
Reject this JIRA if this has already been done.