Both debfoster and aptitude keep track of which packages the user
installed explicitly, and which are only installed to satisfy
dependancies. If the two programs kept this list in the same file, then
they would be able to interoperate nicely; I could take my existing
debfoster systems and run aptitude on them and it would know which
packages I had explicitly installed. And if I installed something new
with aptitude, debfoster would know I did that as well.

Debfoster uses /var/lib/debfoster/keepers, while aptitude uses a more
complicated /var/lib/aptitude/pkgstates. Both files are not all that
hard to parse, so I'd hope something could be worked out. At first
glance, it seems that aptitude's pkgstates file is the more inclusive
file format.

(Of course, in an ideal would dpkg and apt would keep track of this too,
and it would be just another flag in the dpkg status file, but I am not
holding my breath on that. Getting interoperability between the two best
existing debian package management tools would be an excellent first
step.)

For now, here is how debfoster info can be imported into aptitude.

1. Make sure that aptitude is set to not remove unused packages
   automatically. **VERY IMPORTANT**
2. Mark all packages as being installed automatically.
    > aptitude markauto ~Aunstable'
3. Mark all of debfoster's packages as being installed manually.
    > aptitude unmarkauto `grep -v ^- /var/lib/debfoster/keepers`
4. Reverse step #1, and have autitude act on the result.

I found it was helpful to limit to ~M and go through the set of
automatically selected installed and upgradable packages, and mark some
of the more important ones as non-automatically selected. Just so I
don't lost binutils if I remove debhelper and lintian..