add nixos-options package

packages/nixos-options/default.nix

@@ -0,0 +1,55 @@
+{
+  lib,
+  pkgs,
+  inputs,
+  stdenv,
+  supportedSystems ? [ "x86_64-linux" ],
+}:
+
+with import "${inputs.nixpkgs}/pkgs/top-level/release-lib.nix" { inherit supportedSystems; };
+
+let
+
+  version = "nixos-unstable";
+  versionSuffix = "pre${toString pkgs.revCount}.${pkgs.shortRev}";
+
+  buildFromConfig =
+    module: sel:
+    forAllSystems (
+      system:
+      lib.hydraJob (
+        sel
+          (import "${inputs.nixpkgs}/nixos/lib/eval-config.nix" {
+            inherit system;
+            modules = [
+              module
+              (
+                { config, ... }:
+                {
+                  system.nixos.versionSuffix = versionSuffix;
+                  system.nixos.revision = pkgs.rev or pkgs.shortRev;
+                  # At creation time we do not have state yet, so just default to latest.
+                  system.stateVersion = config.system.nixos.version;
+                  fileSystems."/".device = mkDefault "/dev/sda1";
+                  boot.loader.grub.device = mkDefault "/dev/sda";
+                }
+              )
+            ];
+          }).config
+      )
+    );
+
+  options =
+    (buildFromConfig ({ ... }: { }) (config: config.system.build.manual.optionsJSON)).x86_64-linux;
+in
+stdenv.mkDerivation {
+  pname = "nixos-options";
+  inherit version;
+
+  src = inputs.nixpkgs;
+
+  installPhase = ''
+    mkdir $out
+    cp -r ${options} $out/options
+  '';
+}