os host action:
        #!/usr/bin/env bash
        set -euo pipefail

        nixpkgs=$(nix-instantiate --eval -E "let sources = import ./nix/sources.nix {}; in sources.nixpkgs.outPath" | jq -r .)
        sudo nixos-rebuild {{ action }} \
                -I nixpkgs=${nixpkgs} \
                -I nixos-config=./nix/configurations/{{ host }}.nix \
                --fast \
                --file ./default.nix \
                --attr "nixosConfigurations.{{ host }}"

install host:
        #!/usr/bin/env bash
        set -euo pipefail

        nixpkgs=$(nix-instantiate --eval -E "let sources = import ./nix/sources.nix {}; in sources.nixpkgs.outPath" | jq -r .)
        sudo nixos-install \
                -I nixpkgs=${nixpkgs} \
                -I nixos-config=./nix/configurations/{{ host }}.nix \
                --file ./default.nix \
                --attr "nixosConfigurations.{{ host }}"

env name action profilePath="~/.environments":
        #!/usr/bin/env bash
        set -euo pipefail

        # 1) realize the buildEnv derivation
        # 2) set the environment to it
        drv=$(nix-build -E "
                let sources = import ./nix/sources.nix {};
                    pkgs = import sources.nixpkgs {
                      overlays = [
                        (import ./nix/overlays)
                        (import ./nix/overlays/packages.nix)
                      ];
                    };
                 in pkgs.callPackage ./nix/environments/{{ name }}.nix {}
                ")
        mkdir -p {{ profilePath }}
        nix-env --{{ action }} "$drv" --profile {{ profilePath }}"/{{ name }}"

update:
        niv update nixpkgs
        niv update nur