Install matching set of software while preserving aptitude auto/manual install info

["Brian McKee" <brian.mckee@gmail.com>]

Hi All,

I'd like to 'clone' the installed software on a machine.   I can find
lots of references to this procedure
> Backup installed package list on current machine
> dpkg --get-selections > selections.txt
> move selections.txt to the new machine Set package list on new machine and install packages
> dpkg --set-selections < selections.txt
> apt-get update
> apt-get upgrade

What I can't find, but I know I've seen, is a way to do it using
aptitude that preserves aptitude's knowledge of what was installed
manually vs automatically.
Can someone throw me a link (or a cluestick)

Brian