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From: Bill Fenner <fenner@parc.xerox.com>
To: freebsd-ports@freebsd.org
Subject: Versioning bsd.port.mk
Message-Id: <97Aug21.134334pdt.177512@crevenia.parc.xerox.com>
Date: Thu, 21 Aug 1997 13:43:22 PDT
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Sorry if this is a duplicate; I didn't see my original message either
come back to me via the mailing list or in the archive.

Adding the following to bsd.port.mk will give you a variable which is
the check-in date of the existing bsd.port.mk (this doesn't help people
who have their own CVS trees into which they check FreeBSD sources).

BSD_PORT_MK_DATE=    $$Date: $$
BSD_PORT_MK_DATE:=   ${BSD_PORT_MK_DATE:M[0-9]*/[0-9]*}
BSD_PORT_MK_DATE:=   ${BSD_PORT_MK_DATE:S/\///g}

Then bsd.port.mk could have something like

.if defined(NEED_MK_VERSION) && (${NEED_MK_VERSION} > ${BSD_PORT_MK_DATE})
	${ECHO_MSG} "===> WARNING: you probably need a newer bsd.port.mk to build this port"
.endif

in bsd.port.mk, and port Makefiles could contain NEED_MK_VERSION= .

  Bill