Version Not Found

go.etcd.io/etcd v0.5.0-alpha.2.0.20141108004402-0b493ac8d4d8

The requested version v0.5.0-alpha.2.0.20141108004402-0b493ac8d4d8 cannot be found for package go.etcd.io/etcd. Go to the default version (v0.4.9) instead.