To repro:

• Start two replica set nodes
• do rs.add("arbiter-west:27017", true) where "arbiter-west" does not exist

You get the following error message:

{
"assertion" : "need most members up to reconfigure, not ok : arbiter-west",
"assertionCode" : 13144,
"errmsg" : "db assertion failure",
"ok" : 0
}

However, the logs look like the following:
Wed May 25 22:21:41 [conn2] replSet replSetReconfig config object parses ok, 3 members specified
Wed May 25 22:21:41 [conn2] warning: getaddrinfo("arbiter-west") failed: Name or service not known
Wed May 25 22:21:41 [conn2] getaddrinfo("arbiter-west") failed: Name or service not known
Wed May 25 22:21:41 [conn2] warning: getaddrinfo("arbiter-west") failed: Name or service not known
Wed May 25 22:21:41 [conn2] getaddrinfo("arbiter-west") failed: Name or service not known
Wed May 25 22:21:41 [conn2] warning: getaddrinfo("arbiter-west") failed: Name or service not known
Wed May 25 22:21:41 [conn2] getaddrinfo("arbiter-west") failed: Name or service not known
Wed May 25 22:21:41 [conn2] getaddrinfo("arbiter-west") failed: Name or service not known
Wed May 25 22:21:41 [conn2] replSet cmufcc requestHeartbeat arbiter-west:27017 : 9001 sock et exception [6]
Wed May 25 22:21:41 [conn2] replSet replSetReconfig exception: need most members up to rec onfigure, not ok : arbiter-west:27017

Problem
======
Message in shell does not really point to source of error. The error is a failed name resolution, but the exception in the shell is a configuration problem.

Expected Output
======
One of:
1. nested error messages
2. first error message ("name resolution failed" or "couldn't connect")