I just upgraded several PC to Ubuntu Trusty 14.04. For this, I used to install everything from scratch to get a clean system, keeping only /home (and /etc for reference).
This time however I upgraded using the upgrade tool, and I want to know what differences my PCs have compared to a nominal system. Because I installed many different packages from different sources, and might have edited some files here and there. Of course I know that apt should handle everything auto-magically, but I'm the paranoid type, and I really want to make sure.
Basically, here what I'd like to have:
Get a list of all packages installed and for each of them, the repository it is coming from (if available). This would be basically an
apt-cache policyfor each package, but summarized in a neat list.
For packages coming from "unofficial sources", an indication whether there is a version available from the official sources (I mean the repo listed in /etc/apt/sources.list).
Sometime I installed patched packages from some 3rd-party, and this package is not updated because of conflicting version number. I want to have a list telling me whether it makes sense to fall-back to official version.
The list of all files on the file system coming from an installed package (incl. configuration files), but that have been modified afterwards.
The list of all files on the file system (excluding /home, and possibly /etc) that are not coming from an installed package.
Basically I want to know the differences that my system have if I did the upgrade versus a clean install, and decide on a case by case basis whether these differences might cause some instability.