introduce flake that exports nixpkgs with overlays

.gitignore

@@ -1 +1,3 @@
 /result
+# we ignore flake.lock because this isn't intended to pin a specific version of nixpkgs
+/flake.lock

default.nix

@@ -1,52 +1,5 @@
 { ... }:
-
 {
-  imports = [
+  imports = [ ./module.nix ];
-    ./modules/ghidra-server
+  nixpkgs.overlays = import ./overlay.nix;
-  ];
-
-  nixpkgs.overlays = [
-    (final: prev: {
-      fetchFromSteam = prev.callPackage ./lib/fetchsteam {};
-      fetchb4 = prev.callPackage ./lib/fetchb4 {};
-
-      gitSource = prev.callPackage ./lib/git-source {};
-
-      makeSquashFs = prev.callPackage ./lib/make-squashfs {};
-      makeHpcDist = final.callPackage ./lib/make-hpc-dist {};
-
-      ghidra_headless = prev.ghidra.override {
-        openjdk17 = prev.openjdk17_headless;
-      };
-
-
-      # stuff that tracks upstream
-      ghidra = final.callPackage ./pkgs/ghidra-xenia/build.nix {
-        protobuf = final.protobuf_21;
-      };
-      ghidra-extensions = final.lib.recurseIntoAttrs (final.callPackage ./pkgs/ghidra-xenia/extensions.nix { });
-      ghidra-bin = final.callPackage ./pkgs/ghidra-xenia { };  
-
-      kicad = final.callPackage ./pkgs/kicad-xenia { };
-      kicadAddons = final.lib.recurseIntoAttrs (final.callPackage ./pkgs/kicad-xenia/addons {});
-      # end stuff that tracks upstream
-
-
-      ocamlPackages = prev.ocamlPackages.overrideScope (ofinal: oprev: {
-        ppx_unicode = ofinal.callPackage ./pkgs/ocaml/ppx_unicode {};
-        xlog = ofinal.callPackage ./pkgs/ocaml/xlog {};
-      });
-
-      python312Packages = prev.python312Packages.overrideScope (pfinal: pprev: {
-        feedvalidator = pfinal.callPackage ./pkgs/python/feedvalidator {};
-      });
-
-      # add to top level because it has a binary
-      feedvalidator = final.python312Packages.feedvalidator;
-
-      outer-wilds-text-adventure = prev.callPackage ./pkgs/games/outer-wilds-text-adventure {};
-
-      mkNginxServer = prev.callPackage ./lib/dev-nginx {};
-    })
-  ];
 }

flake.nix

@@ -0,0 +1,37 @@
+{
+  description = "dragnpkgs together with nixpkgs and lix";
+
+  inputs = {
+    lix-module = {
+      url = "https://git.lix.systems/lix-project/nixos-module/archive/2.91.0.tar.gz";
+      flake = false;
+    };
+    lix = {
+      url = "https://git.lix.systems/lix-project/lix/archive/2.91.0.tar.gz";
+      flake = false;
+    };
+  };
+
+  outputs = { self, nixpkgs, lix, lix-module }:
+    let
+      overlays = [
+        (import ./overlay.nix)
+        (import "${lix-module}/overlay.nix" { inherit lix; })
+      ];
+      forAllSystems = nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed;
+    in {
+      lib = nixpkgs.lib.extend (final: prev: {
+        nixosSystem = (args: prev.nixosSystem {
+          modules = args.modules ++ [
+            ({ ... }: { nixpkgs.overlays = overlays; })
+          ];
+        } // builtins.removeAttrs args [ "modules" ]);
+      });
+
+      legacyPackages = forAllSystems (system:
+        nixpkgs.legacyPackages.${system}.appendOverlays overlays
+      );
+
+      nixosModules = nixpkgs.nixosModules;
+    };
+}

module.nix

@@ -0,0 +1,5 @@
+{ ... }: {
+  imports = [
+    ./modules/ghidra-server
+  ];
+}

overlay.nix

@@ -0,0 +1,42 @@
+final: prev: {
+  fetchFromSteam = prev.callPackage ./lib/fetchsteam {};
+  fetchb4 = prev.callPackage ./lib/fetchb4 {};
+
+  gitSource = prev.callPackage ./lib/git-source {};
+
+  makeSquashFs = prev.callPackage ./lib/make-squashfs {};
+  makeHpcDist = final.callPackage ./lib/make-hpc-dist {};
+
+  ghidra_headless = prev.ghidra.override {
+    openjdk17 = prev.openjdk17_headless;
+  };
+
+
+  # stuff that tracks upstream
+  ghidra = final.callPackage ./pkgs/ghidra-xenia/build.nix {
+    protobuf = final.protobuf_21;
+  };
+  ghidra-extensions = final.lib.recurseIntoAttrs (final.callPackage ./pkgs/ghidra-xenia/extensions.nix { });
+  ghidra-bin = final.callPackage ./pkgs/ghidra-xenia { };  
+
+  kicad = final.callPackage ./pkgs/kicad-xenia { };
+  kicadAddons = final.lib.recurseIntoAttrs (final.callPackage ./pkgs/kicad-xenia/addons {});
+  # end stuff that tracks upstream
+
+
+  ocamlPackages = prev.ocamlPackages.overrideScope (ofinal: oprev: {
+    ppx_unicode = ofinal.callPackage ./pkgs/ocaml/ppx_unicode {};
+    xlog = ofinal.callPackage ./pkgs/ocaml/xlog {};
+  });
+
+  python312Packages = prev.python312Packages.overrideScope (pfinal: pprev: {
+    feedvalidator = pfinal.callPackage ./pkgs/python/feedvalidator {};
+  });
+
+  # add to top level because it has a binary
+  feedvalidator = final.python312Packages.feedvalidator;
+
+  outer-wilds-text-adventure = prev.callPackage ./pkgs/games/outer-wilds-text-adventure {};
+
+  mkNginxServer = prev.callPackage ./lib/dev-nginx {};
+}