dhclient can't limit bpf descriptor?

Opened up an old VM from a month or so ago (r257910) and dhclient won’t start.

Specifically, dhclient complains (when run by root):
 “can’t limit bpf descriptor: Bad address”
and then immediately exits.

What does this mean?   I don’t know anything about the capabilities
framework and certainly haven’t configured it in any way.

I’ve upgraded Parallels and the Mac OS system that Parallels
is running on, so it could be related to that...

Tim