Creating user in CLI requires mandatory full name, but creating user through UI accepts optional full name

dons-mbp:bin don$ ./couchbase-cli user-manage -c 127.0.0.1:8091 -u Administrator -p password --set --rbac-username jdoe --rbac-password cbpass --roles bucket_admin['*'],replication_admin --auth-type builtin
ERROR: --rbac-name is requires with the --set option

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I expected the above to work even though rbac-name didn't have a value, because it's optional