Nice tricks I found out trying to unfuck my laptop's setup, all my fault:

 * You can use `snapshot.debian.org` to recover packages for any date for any release that was available at that date.
   I actually new this, but somehow I forgot. I used
   `deb http://snapshot.debian.org/archive/debian/20150720T214439Z/ testing main`.

 * For that you have to disable the `Packages`-file-too-old check, which I have never seen, ever. Put this in any file
   in your `/etc/apt.conf.d` dir:

```perl
Acquire {
    Check-Valid-Until "false";
}
```

 * `aptitude` has a menu bar (activate with `C-t`), a preferences dialog, and you can set it up so any operation with a
   package moves down the cursor. Finally I figure that out.

 * It also has a `dselect` theme, but I was not brave enough to try it (for the record, I love `dselect`, I miss the
   fact that it shows how dependencies are resolved in the moment they're needed).

 * You can disable `aptitude`'s resolver (`-o Aptitude::ProblemResolver::StepLimit=0`), but it doesn't make the UI *that*
   much more responsive (???).

 * `digikam` is not on `testing` right now. It [FTBFS with `gcc5`](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=777833)
   and [has a licence problem](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787349).

 * Don't ride `Debian sid` right now, it's suffering a
   [gcc transition](https://release.debian.org/transitions/html/libstdc++6.html) and it might take a while.