bug#62379: /gnu/store/.links filling the hard drive on foreign distro

[Elias Kueny <elias.kueny@posteo.net>]

Hello,

I'm using guix over a foreign distro (Ubuntu 22.04). I initially installed guix from the Ubuntu repositories (version 1.3.0-4), and updated as user with guix pull (work computer: I don't have root access to run the installer script).

The problem is the size of /gnu/store/.links: after garbage collection with "guix gc --delete-generations=1w", /gnu/store is 17.4 GB in total, and /gnu/store/.links is 14.5 GB (344120 items, ranging from 93 MB to 4.1 kB each). The garbage collector prints that "currently hard linking saves 3717.77 MiB".
With a 40GB hard drive, the gnu store regularly fills up all the available space if I'm not careful. I found from an old issue (https://issues.guix.gnu.org/24937#1) that 10 millions links should need around 700 MB, so this sounds like a bug.

After garbage collection, there are only 16 profiles left in /var/guix/profiles/per-user/ for my account: 2 for current-guix, 2 for guix-profile, and the rest for guix-home (where almost every program is installed), plus one guix shell profile I keep activated during gc to not uninstall it. I can't check for the root account, but I'm guessing it contains only the profile of the initial guix installation. There are no other users.

I tried uninstalling the original guix from the Ubuntu repositories in case the issue is due to some interference between it and the current guix I pulled as user, but /var/guix/daemon-socket/socket was gone with it, so I couldn't try to run the garbage collection.

Elias