What is the correct way to override MASTER_SITES in /etc/mk.conf?
I have a local ftp server with all of pkgsrc/distfiles, and want
my various machines to try it first before looking out on the net.
I have tried the following in /etc/mk.conf, but I get an error
that says "Variable MASTER_SITES is recursive" in /usr/src when 
building.  It seems to work fine for /usr/pkgsrc though.
/etc/mk.conf:
FETCH_BEFORE_ARGS=-p
MASTER_SITES:= \
	ftp://frakir/pub/NetBSD/packages/distfiles/${DIST_SUBDIR}/ ${MASTER_SITES}

Is this correct?  What I want is to look locally first, not completely
override the distribution sites.

-Andrew 
-- 
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Andrew Gillham                            | This space left blank
gillham@whirlpool.com                     | inadvertently.
I speak for myself, not for my employer.  | Contact the publisher.