anchor.diff:          if system == "x86_64-cygwin" then prehookCygwin else
           prehookBase;
   
  -      extraNativeBuildInputs =
  -        if system == "i686-cygwin" then extraNativeBuildInputsCygwin else
  +      extraNativeBuildInputs = extraNativeBuildInputs ++
  +        (if system == "i686-cygwin" then extraNativeBuildInputsCygwin else
           if system == "x86_64-cygwin" then extraNativeBuildInputsCygwin else
  -        [];
  +        []);
   
         initialPath = extraPath ++ path;
   
  
positive.code:       inherit (prevStage.stdenv) cc fetchurl;
        extraPath = [ prevStage.xz ];
        overrides = self: super: { inherit (prevStage) xz; };
      };
    })
  
  
negative.code:   # A function that builds a "native" stdenv (one that uses tools in
    # /usr etc.).
    makeStdenv =
      { cc, fetchurl, extraPath ? [], overrides ? (self: super: { }), extraNativeBuildInputs ? [] }:
  
      import ../generic {
        buildPlatform = localSystem;
  