Nix Garbage Collection Here's a quick recipe:
nix-channel --update (descriptions (derivations) of all software) nix-env -u --always (upgrade installed packages) rm /nix/var/nix/gcroots/auto/* nix-collect-garbage -d
Go have a look through
/nix/var/nix/gcroots/. These are the garbage collection roots.
Whatever they point to and say "I still need that" should be protected in a garbage