Error: 100: Key not found or empty ip

The docker run command to set up the couchbase cluster resulted in:
...
[X-Fleet]
MachineOf=couchbase_node@3.service
2015/08/10 14:03:53 Launch fleet unit couchbase_sidekick (3)
2015/08/10 14:03:54 response body:
2015/08/10 14:03:54 Waiting for cluster to be up ..
2015/08/10 14:03:54 Connect to etcd on localhost
2015/08/10 14:03:54 FindLiveNode returned err: Error getting key. Err: 100: Key not found (/couchbase.com/couchbase-node-state) [1715] or empty ip
2015/08/10 14:03:54 Sleeping 10 seconds
...
2015/08/10 15:54:54 FindLiveNode returned err: Error getting key. Err: 100: Key not found (/couchbase.com/couchbase-node-state) [14376] or empty ip
2015/08/10 15:54:54 Sleeping 370 seconds

As you can see, the last two lines repeated, with the sleep interval being incremented by 10 seconds for each attempt. I let it try for over 90 minutes before finally hitting ctr+c.

Not sure why it would not be able to find the key it needs. The CoreOS cluster status is green.

I am following the directions from here: https://github.com/couchbaselabs/couchbase-server-coreos

Thanks for any assistance you can provide!