apt-rdepends installs a shell command (also
apt-rdepends) that gives a clean list of all dependencies. Reverse searching is also possible. I needed something like this in Iraq, when I was upgrading by hand due to a lack of internet connection for my laptop.
Interestingly, Synaptic has grown a script-maker for offline package changes. It generates a script that you use on a connected machine to download the right packages. I could have used that, too...
Now they are merely of academic interest - unless I go back.
Instead of using the
apt-rdepends package, you can get the same result using the
apt-cache rdepends packagename command.