I built lldpd on a NetBSD 8/amd64 system, without your patch, with
pretty up to date packages (definitely post Q3). It built fine. I then
grepped in the workdir and found only a reference in a bl3d snmp header,
but that file says no pcre is used.
I am building on 9, also and will check that, but the machine is very
slow (2006 mac notebook).
It may be that on some systems, snmp needs pcre, but if lldpd doesn't
itself ask for pcre, then the right fix is to add pcre to the bl3 of
that thing that asks for it.
So: Can you explain where the request for pcre comes from?