anchor.diff:  
     enableParallelBuilding = true;
   
  -  postPatch = ''
  -    sed -i -e 's/8\.6\.1|8\.7\.0|8\.7\.1)/8.6.1|8.7.0|8.7.1|8.7.2)/' configure
  -  '';
  +  patches = [ (fetchpatch {
  +    url = "https://github.com/AbsInt/CompCert/commit/679ecfeaa24c0615fa1999e9582bf2af6a9f35e7.patch";
  +   sha256 = "04yrn6dp57aw6lmlr4yssjlx9cxix0mlmaw7gfhwyz5bzqc2za1a";
  +  })];
   
     configurePhase = ''
       substituteInPlace ./configure --replace '{toolprefix}gcc' '{toolprefix}cc'
  
positive.code: 
  stdenv.mkDerivation rec {
    name    = "compcert-${version}";
    version = "3.2";
  
    src = fetchurl {
      url    = "http://compcert.inria.fr/release/${name}.tgz";
      sha256 = "11q4121s0rxva63njjwya7syfx9w0p4hzr6avh8s57vfbrcakc93";
    };
  
    buildInputs = [ coq ]
  
negative.code: { stdenv, lib, fetchurl, fetchpatch
  , coq, ocamlPackages
  , tools ? stdenv.cc
  }:
  