anchor.diff:        inherit (prevStage.stdenv) cc fetchurl;
         extraPath = [ prevStage.xz ];
         overrides = self: super: { inherit (prevStage) xz; };
  +      extraNativeBuildInputs = if localSystem.isLinux then [ prevStage.patchelf ] else [];
       };
     })
   
  
positive.code:         if system == "x86_64-cygwin" then prehookCygwin else
          prehookBase;
  
        extraNativeBuildInputs =
          if system == "i686-cygwin" then extraNativeBuildInputsCygwin else
          if system == "x86_64-cygwin" then extraNativeBuildInputsCygwin else
          [];
  
        initialPath = extraPath ++ path;
  
  
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;
  