We are using an include directory for zabbix_agent configuration user parameters which are managed by rpm. When rpm update performed there will be zabbix_agent-local.conf and zabbix_agent -local.conf.rpmnew in the include directory.
zabbix agent would not start if there is a .rpmnew file in the directory. Error is "duplicate key". zabbix_agent trying to parse both files thus duplicate entries

zabbix agent should ignore any files other than normal conf or .rpmnew files ('.' files)