anchor.diff:          ]
   
       ++ stdenv.lib.optional stdenv.isDarwin ./darwin-arch.patch;
  -  
  +
   in
   
   stdenv.mkDerivation {
  
positive.code: 
    patches = patchesCross false;
  
    buildNativeInputs = [ perl ];
  
    # On x86_64-darwin, "./config" misdetects the system as
  
negative.code: 
    configureFlags = "shared --libdir=lib";
  
    makeFlags = "MANDIR=$(man)/share/man";
  
    postInstall =
      ''
  