For anyone else reading this, I ended up with the following couple of
lines which are enough for dh-make-perl. apt-file itself ignores the
new file since I guess it goes from only those named sources.list, which
may even be a good thing. At any rate it gets the deps for personal
stuff, other dh-make-perl stuff, stuff no longer in the archive, etc.
#!/bin/sh
arch=`dpkg --print-architecture`;
outname="/var/cache/apt/apt-file/installed_Contents-$arch.gz"
echo "writing $outname"
(echo "FILE LOCATION";
dpkg --search '*' \
| sed -n -e 's/, /,/g' \
-e 's%^\([^ :]*\): /\(.*\)%\2 \1%p' ) \
| gzip - >$outname
ls -l $outname
exit 0
