anchor.diff:    };
     "8.5" = {
       version = "0.6";
  -    rev = "v0.6";
       sha256 = "0qvar8gfbrcs9fmvkph5asqz4l5fi63caykx3bsn8zf0xllkwv0n";
     };
   };
  
positive.code:   src = fetchFromGitHub {
      owner = "Karmaki";
      repo = "coq-dpdgraph";
      inherit (param) rev sha256;
    };
  
    nativeBuildInputs = [ autoreconfHook ];
  
negative.code: { stdenv, fetchFromGitHub, autoreconfHook, coq }:
  
  let params = {
    "8.11" = {
      version = "0.6.7";
      sha256 = "01vpi7scvkl4ls1z2k2x9zd65wflzb667idj759859hlz3ps9z09";
    };
    "8.10" = {
      version = "0.6.6";
      sha256 = "1gjrm5zjzw4cisiwdr5b3iqa7s4cssa220xr0k96rwgk61rcjd8w";
    };
    "8.9" = {
      version = "0.6.5";
      sha256 = "1f34z24yg05b1096gqv36jr3vffkcjkf9qncii3pzhhvagxd0w2f";
    };
    "8.8" = {
      version = "0.6.3";
      rev = "0acbd0a594c7e927574d5f212cc73a486b5305d2";
  