Query returns service_not_available if connection string has 'localhost'

Noticed this today, with the current master (1780621...).   The fit tests use couchbase://localhost for the connection string, which always was fine.  But, with this sha and the 2 after it, I cannot perform a query at all.   I get the service_not_available error.  Just changing to couchbase://127.0.0.1 and I'm fine.  However, I can do kv operations without an issue, using localhost