Pinning from different sources

[Josh Litherland <josh@emperorlinux.com>]

I'm attempting to use pinning to manage the interaction of two different
sources I want to use.  The behavior I want is to default to sourceA,
and go to sourceB if and only if

o) a named package does not exist in sourceA, or
o) sourceB is explicitly requested on the command line (with -t,
	or withpackagename/release construct)

I've figured out a pin that successfully identifies sourceA and sourceB,
but the priorities aren't working the way I expect from a reading of
apt_preferences(5).  I'm either getting packages from sourceB any time
there's a newer version in that repository, or I'm not getting them at
all unless I explicitly name sourceB.

What pin-priorities should I set on sourceA and sourceB to get the
behavior described above ?

Thanks !

-- 
Josh Litherland <josh@emperorlinux.com>
Emperor Linux, Inc.