{
  description = "A very basic flake";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    # nixvirt = {
    #   url = "https://flakehub.com/f/AshleyYakeley/NixVirt/*.tar.gz";
    #   inputs.nixpkgs.follows = "nixpkgs";
    # };
    nixvirt.url = "github:Nomkid/NixVirt";
    zig2nix.url = "github:Cloudef/zig2nix";
    # symlink.url = "github:schuelermine/nix-symlink";
    # zig-libvirt.url = "github:Nomkid/zig-libvirt";
  };

  outputs = { self, nixpkgs, flake-utils, nixvirt, zig2nix }: 
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        oslib = import ./os/lib.nix { inherit pkgs system nixvirt; };
        inherit (oslib) osdb;

        zig-env = zig2nix.outputs.zig-env.${system} { zig = zig2nix.outputs.packages.${system}.zig.master.bin; };

        # hello-vm = oslib.mkVM {
        #   name = "hello";
        #   uuid = "c0c49ae7-6fe4-4c39-a8ae-c80c6b689344";
        #   arch = "x86_64";
        #   isos.beforeInstall = [
        #     { index = 1; file = "${osdb.windows."6.1.7601".professional.x86_64.installer}/out.iso"; }
        #     { index = 2; file = "${osdb.windows."6.1.7601".professional.x86_64.unattend}/out.iso"; }
        #   ];
        # };
      in {
        mkFlake = config: let
          vm = oslib.mkVM {
            inherit (config) name uuid;
            beforeInstall = [
              { index = 1; file = "${osdb.${config.os.name}.${config.os.version}.${config.os.edition}.${config.os.arch}.installer}/out.iso"; }
              { index = 2; file = "${osdb.${config.os.name}.${config.os.version}.${config.os.edition}.${config.os.arch}.unattend}/out.iso"; }
            ];
          };
        in {
          packages.volume = vm.volume;
          packages.beforeInstall = vm.beforeInstallDrv;
          packages.afterInstall = vm.afterInstallDrv;
          packages.beforeBoot = vm.beforeBootDrv;
          packages.afterBoot = vm.afterBootDrv;
        };

        apps = {
          # hello-start-vm = flake-utils.lib.mkApp {
          #   drv = hello-vm.start-vm;
          #   exePath = "";
          # };
          default = zig-env.app-no-root [] "zig build run -- \"$@\"";
        };

        devShells.default = zig-env.mkShell {
          nativeBuildInputs = [ pkgs.libvirt.outPath ];
        };

        # For debugging.
        inherit oslib;
      }
    );
}