anchor.diff: -{ stdenv, fetchurl, autoconf, automake, libtool }:
  +{ stdenv, fetchurl }:
   let
     s = # Generated upstream information
     rec {
  
positive.code:     url="http://www.ivmaisoft.com/_bin/atomic_ops/libatomic_ops-7.4.2.tar.gz";
      sha256="1pdm0h1y7bgkczr8byg20r6bq15m5072cqm5pny4f9crc9gn3yh4";
    };
    
    buildInputs = stdenv.lib.optionals stdenv.isCygwin [ autoconf automake libtool ];
  
  in stdenv.mkDerivation {
    inherit (s) name version;
    inherit buildInputs;
  
negative.code:   src = fetchurl {
      inherit (s) url sha256;
    };
  
    meta = {
      inherit (s) version;
  