{
  description = "artemist's NixOS packages and shells for development";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
  };

  outputs =
    { self, nixpkgs }:
    let
      inherit (nixpkgs) lib;
      makePkgs =
        system:
        import nixpkgs {
          inherit system;
          overlays = [ self.overlays.default ];
        };
      forAllSystems =
        f:
        lib.listToAttrs (
          map (system: {
            name = system;
            value = f (makePkgs system);
          }) lib.systems.flakeExposed
        );
      makeDummy =
        pkg:
        if lib.isDerivation pkg then
          pkg
        else
          pkg
          // {
            type = "derivation";
            name = "dummy-attrset";
          };
    in
    {
      formatter = forAllSystems (pkgs: pkgs.nixfmt-rfc-style);

      devShells = forAllSystems (pkgs: {
        armTrustedFirmware = pkgs.callPackage ./shells/armTrustedFirmware { };
        plotter = pkgs.callPackage ./shells/plotter { };
        ryujinx = pkgs.callPackage ./shells/ryujinx { };
        zephyr = pkgs.callPackage ./shells/zephyr { };
      });

      packages = forAllSystems (
        pkgs:
        builtins.listToAttrs (
          let
            names = builtins.attrNames (self.overlays.default pkgs pkgs);
          in
          lib.concatMap (
            name:
            lib.optional (builtins.typeOf pkgs.${name} == "set") {
              inherit name;
              value = makeDummy pkgs.${name};
            }
          ) names
        )
      );

      overlays.default = final: prev: {
        apotris = final.callPackage ./packages/apotris { };
        attic = final.callPackage ./packages/attic { };
        attic-client = final.attic.override { clientOnly = true; };
        cups-dymo-patched = final.callPackage ./packages/cups-dymo { };
        cynthion = final.callPackage ./packages/cynthion { };
        gbeplus = final.callPackage ./packages/gbeplus { };
        hactoolnet = final.callPackage ./packages/hactoolnet { };
        ipsw = final.callPackage ./packages/ipsw { };
        jlink = final.callPackage ./packages/jlink { };
        packetry = final.callPackage ./packages/packetry { };
        stlink-tool = final.callPackage ./packages/stlink-tool { };
        zephyrPackages = final.callPackage ./packages/zephyr { };

        inherit (final.python3.pkgs) axicli vpype;

        inkscape-extensions = prev.inkscape-extensions // {
          axidraw = final.callPackage ./packages/axidraw/inkscape.nix { };
        };

        kernelPatches = prev.kernelPatches // final.callPackage ./packages/kernelPatches { };

        pythonPackagesExtensions = prev.pythonPackagesExtensions ++ [
          (
            pythonFinal: pythonPrev:
            {
              pnoise = final.callPackage ./packages/pnoise { python3 = pythonFinal; };
              vpype = final.callPackage ./packages/vpype { python3 = pythonFinal; };
              vpype-gcode = final.callPackage ./packages/vpype-gcode { python3 = pythonFinal; };
            }
            // (final.callPackage ./packages/axidraw/modules.nix { python3 = pythonFinal; })
          )
        ];
      };
    };
}