{
  description = "Ivy Bridge Custom Mesa";

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

  outputs = { self, nixpkgs }: 
  let
    systems = ["x86_64-linux"];
    
    forAllSystems = f: nixpkgs.lib.genAttrs systems f;
  in {
    packages = forAllSystems (system:
      let
        pkgs = import nixpkgs { inherit system; };
        
        buildCustomMesa = pkgs: pkgs.mesa.overrideAttrs (old: {
          patches = (old.patches or []) ++ [
            (pkgs.fetchpatch {
              url = "https://raw.githubusercontent.com/elwrcl/intel-hard-graphics/main/hd4000-custom.patch";
              hash = ""; # İlk build'de hash al
            })
          ];
          mesonFlags = (old.mesonFlags or []) ++ [ "-Dgallium-rusticl=true" ];
        });
        
      in {
        mesa-custom = buildCustomMesa pkgs;
        mesa-custom-32 = if system == "x86_64-linux" then 
          buildCustomMesa pkgs.pkgsi686Linux 
        else null;
      }
    );
  };
}