nixos/devices/xmuhk/README.md

install nix

1. Build nix using nix build github:NixOS/nixpkgs/nixos-24.11#nixStatic, upload, create symlink nix-store nix-build etc. pointing to it.
2. Upload .config/nix/nix.conf.

install or update packages

1. On nixos, make sure /public/home/xmuhk/.nix is mounted correctly.
2. Build using sudo nix build --store 'local?store=/public/home/xmuhk/.nix/store&state=/public/home/xmuhk/.nix/state&log=/public/home/xmuhk/.nix/log' .#xmuhk .
3. Diff store using sudo nix-store --store 'local?store=/public/home/xmuhk/.nix/store&state=/public/home/xmuhk/.nix/state&log=/public/home/xmuhk/.nix/log' -qR ./result | grep -Fxv -f <(ssh xmuhk find .nix/store -maxdepth 1 -exec realpath '{}' '\;') | sudo xargs nix-store --store 'local?store=/public/home/xmuhk/.nix/store&state=/public/home/xmuhk/.nix/state&log=/public/home/xmuhk/.nix/log' --export | xz -T0 | pv > xmuhk.nar.xz .
4. Upload xmuhk.nar.xz to hpc.
5. On hpc, pv xmuhk.nar.xz | xz -d | nix-store --import .
6. Create gcroot using nix build /xxx-xmuhk -o .nix/state/gcroots/current, where /xxx-xmuhk is the last path printed by nix-store --import .