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