anchor.diff:    src = fetchFromGitHub {
       owner = "Karmaki";
       repo = "coq-dpdgraph";
  -    inherit (param) rev sha256;
  +    rev = param.rev or "v${param.version}";
  +    inherit (param) sha256;
     };
   
     nativeBuildInputs = [ autoreconfHook ];
  
positive.code: { stdenv, fetchFromGitHub, autoreconfHook, coq }:
  
  let params = {
    "8.8" = {
      version = "0.6.3";
      rev = "0acbd0a594c7e927574d5f212cc73a486b5305d2";
  
negative.code:   };
    "8.5" = {
      version = "0.6";
      sha256 = "0qvar8gfbrcs9fmvkph5asqz4l5fi63caykx3bsn8zf0xllkwv0n";
    };
  };
  