Comment 7 for bug 1267059

I checked and apparently now_auto_removable and pkgs_auto_removable are always the same, as "is_auto_removable" only returns different results _after_ the packages have actually been upgraded. Just marking them does apparently not change the output of is_auto_removable(). I tried to use the ProblemResolver but I didn't get the output of is_auto_removable() to change.

One possible solution is to actually upgrade the packages and then check for autoremovability, then you can make it works as intended. My original patch implemented only an autoremove (same as "apt-get autoremove").