I believe those changes are tracked, there are commands that will tell you what package a file is from (I think it might be apt-file). It's been a while since

I believe those changes are tracked, there are commands that will tell you what package a file is from (I think it might be apt-file). It's been a while since I used apt in depth, but I do know that pacman tracks that and will log error messages if a file already exists. For example when config formats change, if I have /etc/example.yml created already, pacman will throw an error and put the new file at /etc/example.yml.pac-new (or a similar scheme). > (if, say, both app1 and app2 need ImageMagick with different policies) ? Debian typically handles that by building fat binaries/libraries with all the possible options enabled. In cases where there are multiple incompatible options, I'm not an expert, but I believe you create a virtual/meta "package" that can be satisfied by installation of any of the incompatible binaries. Pacman handles it similarly. Gentoo is an oddball in that it tracks a set of system flags and enabled/disables features in builds based on which flags you have set. It's able to do that because it compiles the packages itself, so you can choose the options at install time.