anchor.diff:  
   rustPlatform.buildRustPackage rec {
     pname = "cargo-c";
  -  version = "0.6.13";
  +  version = "0.6.15";
   
     src = stdenv.mkDerivation rec {
       name = "${pname}-source-${version}";
  
positive.code:     '';
    };
  
    cargoSha256 = "0jjkcawcz6wacx22zir9ay1qsi5ffk7c4gwa6jpky4a94zr1h690";
  
    nativeBuildInputs = [ pkg-config ];
    buildInputs = [ openssl ]
  
negative.code:       owner = "lu-zero";
        repo = pname;
        rev = "v${version}";
        sha256 = "04hrk3vy8294vxcsggdpcs8hg3ykzj2564ifsqc4zwz4b4wd1p8l";
      };
      cargoLock = fetchurl {
        url = "https://github.com/lu-zero/${pname}/releases/download/v${version}/Cargo.lock";
        sha256 = "0rqb6ssqsdlm8zbshbxkwxlyy7j7p2gyficavzz33cw9g6fpmzbd";
      };
  
      installPhase = ''
  