Log Message:
   if ${PROG_PAX} is defined, run paxctl on the binary after linking with
   the value of the variable. This way, if you set:
   
       PROG_PAX=+M
   
   in /etc/mk.conf, you get what you deserve.
could this be PROG_PAXCTL?  the current one makes me think of pax(1).
.mrg.