This landed in aws-sdk-go yesterday, breaking the AWS provider in many places:
3c259c9586
Here, with much sedding, grepping, and manual massaging, we attempt to
catch Terraform up to the new `awserr.Error` interface world.
Needs to wait for len(cluster.CacheNodes) == cluster.NumCacheNodes, since
apparently that takes a bit of time and the initial response always has
an empty collection of nodes