[kenmacd]

     du -sh /nix
    187G /nix

This is with

    nix.gc = {
      automatic = true;
      dates = "weekly";
      options = "--delete-older-than 30d";
    };

Cleaning up some direnv versions and a `nix-collect-garbage --delete-older-than 5d` would bring it down to around 40G. For me this isn't _too much_ space, but it's easy for an update to download multiple gigs, so something to keep in mind I guess.

The size of the nix store has never really caused me issues, but ending up with a full `/boot` has. I now always set `boot.loader.systemd-boot.configurationLimit` to avoid these issues.