security/oidentd-2.0.8_2 from ports (IPV6=yes, didn't test without) SIGSEV's for me when a lookup arrives.
I've also stumbled upon this bug.
IPv4 requests gets the response without issues, but IPv6 causes SIGSEGV.
Fix bug title and assign maintainer manually.
As I am a novice, I have no clue, but if I install an older version that I found in my cache, then it works as expected.
I've upgraded to 2.3.1 (+removed files/patch-*) and tried again, it works now.
However dropping privs to nobody/nogroup will break it again so it has to run as root.