serene% xAPI_VERSION_REQUIRED=1 xMONGO_RUBY_DRIVER_CLIENT_DEBUG=1 SERVExR_API='{version: "1"}' MONGODB_URI=mongodb://localhost:14400 bs spec/mongo/server_selector*
                                                                                                                                           
  1) Mongo::ServerSelector::Nearest#select_in_replica_set tag sets provided single candidate matching primary returns an array with the primary
     Failure/Error: raise Error::NoServerAvailable.new(self, cluster, msg)
     
     Mongo::Error::NoServerAvailable:
       No primary server is available in cluster: #<Cluster topology=Single[localhost:14400] servers=[#<Server address=localhost:14400 UNKNOWN NO-MONITORING>]> with timeout=7.01, LT=0.015. The following servers have dead monitor threads: #<Server address=localhost:14400 UNKNOWN NO-MONITORING>
     # ./lib/mongo/server_selector/base.rb:279:in `select_server'
     # ./lib/mongo/cluster.rb:731:in `next_primary'
     # ./spec/support/authorization.rb:151:in `block in included'
     # ./spec/mongo/server_selector/nearest_spec.rb:168:in `block (4 levels) in <top (required)>'
     # ./spec/mongo/server_selector/nearest_spec.rb:185:in `block (6 levels) in <top (required)>'
     # ./spec/mongo/server_selector/nearest_spec.rb:188:in `block (6 levels) in <top (required)>'
     # ./spec/support/background_thread_registry.rb:65:in `block (2 levels) in <top (required)>'