bsd.port.mk broken on FreeBSD 4.7? Or make?

[Peter Beckman]

When trying to build /usr/ports/mail/postfix (just did an update from
cvsup11.us.freebsd.org):

# $FreeBSD: ports/Mk/bsd.port.mk,v 1.529 2006/02/23 15:37:20 ade Exp $

(root) mail : /usr/ports/mail/postfix --> make clean
"/usr/ports/Mk/bsd.port.mk", line 5075: warning: String comparison operator
should be either == or !=
"/usr/ports/Mk/bsd.port.mk", line 5075: Malformed conditional
((${OSVERSION} >= 700007 || (${OSVERSION} < 700000 && ${OSVERSION} >=
600101)))
"/usr/ports/Mk/bsd.port.mk", line 5075: Need an operator
"/usr/ports/Mk/bsd.port.mk", line 5399: if-less endif
"/usr/ports/Mk/bsd.port.mk", line 5399: Need an operator
make: fatal errors encountered -- cannot continue
(root) mail : /usr/ports/mail/postfix --> uname -a
FreeBSD mail.nova.org 4.7-STABLE FreeBSD 4.7-STABLE #4: Mon Oct 14 11:13:46
EDT 2002 i386

I assume my "make" is just too old; what to do?  I found no instructions in
the CHANGES or UPDATING docs, nor on freebsd.org/ports on how to upgrade
make.

I assume I need to update /usr/src and make make from there, but since I
don't see any documented process, I wanted to ask first.

Beckman
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Peter Beckman                                                  Internet Guy
beckman at purplecow.com                             http://www.purplecow.com/
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