heartbeat-2.0.2 automatically detects the presence of net-snmp and does the right thing. However, the ebuild has no dependency on snmp, so there is no automatic way to force it to be emerged. I've attached a patch to the heartbeat-2.0.2 ebuild that adds snmp to the IUSE, and conditionally depends on net-snmp.
Created attachment 79405 [details, diff] patch to heartbeat-2.0.2.ebuild to add snmp dependency
Created attachment 79406 [details] entire modified ebuild
fixed in cvs. Thanks.