https://nixos.org/nix/

aur/nix
    https://aur.archlinux.org/packages/nix/
    https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=nix
    https://github.com/asppsa/aur-nix
    https://github.com/asppsa/aur-nix/blob/master/nix.install