Bug#1119668: apt wants to install a lot of Recommends packages when doing full-upgrade

Hi,

On Sat, Nov 01, 2025 at 11:44:42AM +0100, Daniel Kamil Kozar wrote:
>Thanks Julian. Running with Debug::APT::Solver=3 does seem to highlight the
>actual problem. The issue appears to be caused by Thunar recommending the
>policykit-1-gnome or polkit-1-auth-agent virtual packages which apt to try
>installing Cinnamon as the default ("try it") first choice :
>[…]

I ran into the same problem. In my case, it was nm-connection-editor 
depending on policykit-1-gnome|polkit-1-auth-agent, with 
policykit-1-gnome being dropped from Debian testing a couple months ago. 
Trying to apt install polkit-1-auth-agent and picking a suitable 
alternative fixed the issue for me.

A couple notes/ideas about what would have made this easier to resolve:

1. Debug::APT::Solver=3 is completely undocumented (I tried man 
    apt.conf, and later confirmed by grepping the entire apt sources).

2. apt could have hinted that policykit-1-gnome will become 
    autoremovable after the upgrade that installs cinnamon, then I might 
    have had an idea what to look for.

3. Perhaps a more user-friendly debug option might be added that only 
    shows info about dependency chains for newly installed packages 
    during full-upgrade? If I could do `apt full-upgrade -VV` or 
    something and get an output like "nm-connection-editor → 
    policykit-1-gnome|polkit-1-auth-agent → cinnamon" then I'd 
    immediately know what's going on and what needs to be done to resolve 
    this.

4. Or perhaps if `apt full-upgrade` told me months ago that 
    policykit-1-gnome dropped from the archives and needs replacing?

>In case you want to test this yourself, I could reproduce the very same
>situation in the forky Docker image. Just apt update/upgrade to get it to
>apt 3.1.11, and then do "apt install thunar". You'll see a very similar list of
>packages that I'm getting.

Also note that in today's debian:testing docker image, apt install 
nm-connection-editor makes different choices depending on solver. 3.0 
tries to install cinnamon, legacy solver goes with xfce-polkit.

-- 
Tomáš "liskin" ("Pivník") Janoušek, https://lisk.in/