anchor.diff:        # Whether we should run paxctl to pax-mark binaries.
         needsPax = isLinux;
   
  +      inherit mkDerivation;
  +
         # For convenience, bring in the library functions in lib/ so
         # packages don't have to do that themselves.
         inherit lib;
  
positive.code: 
      // rec {
  
        meta = {
          description = "The default build environment for Unix packages in Nixpkgs";
        };
  
        # Add a utility function to produce derivations that use this
        # stdenv and its shell.
        mkDerivation = attrs:
          let
            pos =
              if attrs.meta.description or null != null then
                unsafeGetAttrPos "description" attrs.meta
              else
                unsafeGetAttrPos "name" attrs;
            pos' = if pos != null then "‘" + pos.file + ":" + toString pos.line + "’" else "«unknown-file»";
          in
          if !allowUnfree
             && (let l = lib.lists.toList attrs.meta.license or []; in lib.lists.elem "unfree" l || lib.lists.elem "unfree-redistributable" l)
             && !allowUnfreePredicate attrs then
            throw ''
              Package ‘${attrs.name}’ in ${pos'} has an unfree license, refusing to evaluate. You can set
                { nixpkgs.config.allowUnfree = true; }
              in configuration.nix to override this. If you use Nix standalone, you can add
                { allowUnfree = true; }
              to ~/.nixpkgs/config.nix.''
          else if !allowBroken && attrs.meta.broken or false then
            throw "you can't use package ‘${attrs.name}’ in ${pos'} because it has been marked as broken"
          else if !allowBroken && attrs.meta.platforms or null != null && !lib.lists.elem result.system attrs.meta.platforms then
            throw "the package ‘${attrs.name}’ in ${pos'} is not supported on ‘${result.system}’"
          else
            lib.addPassthru (derivation (
              (removeAttrs attrs ["meta" "passthru" "crossAttrs"])
              // (let
                buildInputs = attrs.buildInputs or [];
                nativeBuildInputs = attrs.nativeBuildInputs or [];
                propagatedBuildInputs = attrs.propagatedBuildInputs or [];
                propagatedNativeBuildInputs = attrs.propagatedNativeBuildInputs or [];
                crossConfig = attrs.crossConfig or null;
              in
              {
                builder = attrs.realBuilder or shell;
                args = attrs.args or ["-e" (attrs.builder or ./default-builder.sh)];
                stdenv = result;
                system = result.system;
                userHook = config.stdenv.userHook or null;
                __ignoreNulls = true;
  
                # Inputs built by the cross compiler.
                buildInputs = lib.optionals (crossConfig != null) (buildInputs ++ extraBuildInputs');
                propagatedBuildInputs = lib.optionals (crossConfig != null) propagatedBuildInputs;
                # Inputs built by the usual native compiler.
                nativeBuildInputs = nativeBuildInputs ++ lib.optionals (crossConfig == null) (buildInputs ++ extraBuildInputs');
                propagatedNativeBuildInputs = propagatedNativeBuildInputs ++
                  lib.optionals (crossConfig == null) propagatedBuildInputs;
            }))) (
            {
              # The meta attribute is passed in the resulting attribute set,
              # but it's not part of the actual derivation, i.e., it's not
              # passed to the builder and is not a dependency.  But since we
              # include it in the result, it *is* available to nix-env for
              # queries.  We also a meta.position attribute here to
              # identify the source location of the package.
              meta = attrs.meta or {} // (if pos != null then {
                position = pos.file + ":" + (toString pos.line);
              } else {});
              passthru = attrs.passthru or {};
            } //
            # Pass through extra attributes that are not inputs, but
            # should be made available to Nix expressions using the
            # derivation (e.g., in assertions).
            (attrs.passthru or {}));
  
        # Utility flags to test the type of platform.
        isDarwin = system == "x86_64-darwin";
  
negative.code:       gcc
      ];
  
    # Add a utility function to produce derivations that use this
    # stdenv and its shell.
    mkDerivation = attrs:
      let
        pos =
          if attrs.meta.description or null != null then
            unsafeGetAttrPos "description" attrs.meta
          else
            unsafeGetAttrPos "name" attrs;
        pos' = if pos != null then "‘" + pos.file + ":" + toString pos.line + "’" else "«unknown-file»";
      in
      if !allowUnfree
         && (let l = lib.lists.toList attrs.meta.license or []; in lib.lists.elem "unfree" l || lib.lists.elem "unfree-redistributable" l)
         && !allowUnfreePredicate attrs then
        throw ''
          Package ‘${attrs.name}’ in ${pos'} has an unfree license, refusing to evaluate. You can set
            { nixpkgs.config.allowUnfree = true; }
          in configuration.nix to override this. If you use Nix standalone, you can add
            { allowUnfree = true; }
          to ~/.nixpkgs/config.nix.''
      else if !allowBroken && attrs.meta.broken or false then
        throw "you can't use package ‘${attrs.name}’ in ${pos'} because it has been marked as broken"
      else if !allowBroken && attrs.meta.platforms or null != null && !lib.lists.elem result.system attrs.meta.platforms then
        throw "the package ‘${attrs.name}’ in ${pos'} is not supported on ‘${result.system}’"
      else
        lib.addPassthru (derivation (
          (removeAttrs attrs ["meta" "passthru" "crossAttrs"])
          // (let
            buildInputs = attrs.buildInputs or [];
            nativeBuildInputs = attrs.nativeBuildInputs or [];
            propagatedBuildInputs = attrs.propagatedBuildInputs or [];
            propagatedNativeBuildInputs = attrs.propagatedNativeBuildInputs or [];
            crossConfig = attrs.crossConfig or null;
          in
          {
            builder = attrs.realBuilder or shell;
            args = attrs.args or ["-e" (attrs.builder or ./default-builder.sh)];
            stdenv = result;
            system = result.system;
            userHook = config.stdenv.userHook or null;
            __ignoreNulls = true;
  
            # Inputs built by the cross compiler.
            buildInputs = lib.optionals (crossConfig != null) (buildInputs ++ extraBuildInputs');
            propagatedBuildInputs = lib.optionals (crossConfig != null) propagatedBuildInputs;
            # Inputs built by the usual native compiler.
            nativeBuildInputs = nativeBuildInputs ++ lib.optionals (crossConfig == null) (buildInputs ++ extraBuildInputs');
            propagatedNativeBuildInputs = propagatedNativeBuildInputs ++
              lib.optionals (crossConfig == null) propagatedBuildInputs;
        }))) (
        {
          # The meta attribute is passed in the resulting attribute set,
          # but it's not part of the actual derivation, i.e., it's not
          # passed to the builder and is not a dependency.  But since we
          # include it in the result, it *is* available to nix-env for
          # queries.  We also a meta.position attribute here to
          # identify the source location of the package.
          meta = attrs.meta or {} // (if pos != null then {
            position = pos.file + ":" + (toString pos.line);
          } else {});
          passthru = attrs.passthru or {};
        } //
        # Pass through extra attributes that are not inputs, but
        # should be made available to Nix expressions using the
        # derivation (e.g., in assertions).
        (attrs.passthru or {}));
  
    # The stdenv that we are producing.
    result =
  
  