anchor.diff:    # `newScope' for sets of packages in `pkgs' (see e.g. `gnome' below).
     callPackage = pkgs.newScope {};
   
  -  callPackages = lib.callPackagesWith splicedPackages;
  +  callPackages = lib.callPackagesWith splicedPackagesWithXorg;
   
  -  newScope = extra: lib.callPackageWith (splicedPackages // extra);
  +  newScope = extra: lib.callPackageWith (splicedPackagesWithXorg // extra);
   
     # Haskell package sets need this because they reimplement their own
     # `newScope`.
  
positive.code: lib: pkgs: actuallySplice:
  
  let
    defaultBuildBuildScope = pkgs.buildPackages.buildPackages // pkgs.buildPackages.buildPackages.xorg;
    defaultBuildHostScope = pkgs.buildPackages // pkgs.buildPackages.xorg;
    defaultBuildTargetScope =
      if pkgs.stdenv.targetPlatform == pkgs.stdenv.hostPlatform
      then defaultBuildHostScope
      else assert pkgs.stdenv.hostPlatform == pkgs.stdenv.buildPlatform; defaultHostTargetScope;
    defaultHostHostScope = {}; # unimplemented
    defaultHostTargetScope = pkgs // pkgs.xorg;
    defaultTargetTargetScope = pkgs.targetPackages // pkgs.targetPackages.xorg or {};
  
    spliceReal = { pkgsBuildBuild, pkgsBuildHost, pkgsBuildTarget
                 , pkgsHostHost, pkgsHostTarget
  
negative.code:                    } @ args:
      if actuallySplice then spliceReal args else pkgsHostTarget;
  
    splicedPackages = splicePackages rec {
      pkgsBuildBuild = pkgs.buildPackages.buildPackages;
      pkgsBuildHost = pkgs.buildPackages;
      pkgsBuildTarget =
        if pkgs.stdenv.targetPlatform == pkgs.stdenv.hostPlatform
        then pkgsBuildHost
        else assert pkgs.stdenv.hostPlatform == pkgs.stdenv.buildPlatform; pkgsHostTarget;
      pkgsHostHost = {}; # unimplemented
      pkgsHostTarget = pkgs;
      pkgsTargetTarget = pkgs.targetPackages;
    } // {
      # These should never be spliced under any circumstances
      inherit (pkgs) pkgs buildPackages targetPackages;
      inherit (pkgs.stdenv) buildPlatform targetPlatform hostPlatform;
    };
  
    splicedPackagesWithXorg = splicedPackages // splicedPackages.xorg;
  
  in
  
  