Look at the ports for FreeBSD.

   ftp://ftp.freebsd.org/pub/FreeBSD/FreeBSD-current/ports/comms/hylafax/

There it says that you also need:

    bash-1.14.7 & ghostscript-2.6.2

(also found in the ports)

The make file goes to:

   ftp://ftp.sgi.com/sgi/fax/source/

for the source.  FreeBSD and NetBSD should be close enough kin
that you can get this to work (I think?).

Good luck,
Paul