anchor.diff:    };
     "8.5" = {
       version = "0.6";
  -    rev = "v0.6";
       sha256 = "0qvar8gfbrcs9fmvkph5asqz4l5fi63caykx3bsn8zf0xllkwv0n";
     };
   };
  
positive.code: { stdenv, fetchFromGitHub, autoreconfHook, coq }:
  
  let params = {
    "8.8" = {
      version = "0.6.3";
      rev = "0acbd0a594c7e927574d5f212cc73a486b5305d2";
  
negative.code:   src = fetchFromGitHub {
      owner = "Karmaki";
      repo = "coq-dpdgraph";
      rev = param.rev or "v${param.version}";
      inherit (param) sha256;
    };
  
    nativeBuildInputs = [ autoreconfHook ];
  