Interesting, I have taken a stab at maintaining a repo on the nixpkgs and using a --sparse approach, i.e. `git clone --filter=blob:none --sparse --branch nixos-25.11 https://github.com/NixOS/nixpkgs.git nixpkgs-dorion
cd nixpkgs-dorion`
Oh, maybe I had a full clone on my laptop before I started doing shallow fetches, but since fetching takes quite a while I've been using a shallow clone on my workstation.