anchor.diff:  
   buildPythonApplication rec {
     pname = "cvise";
  -  version = "2.4.0";
  +  version = "2.5.0";
   
     src = fetchFromGitHub {
       owner = "marxin";
       repo = "cvise";
  -    rev = "v${version}";
  -    sha256 = "0cfzikkhp91hjgxjk3izzczb8d9p8v9zsfyk6iklk92n5qf1aakq";
  +    rev = "refs/tags/v${version}";
  +    sha256 = "sha256-Nt6Zs3FxO8Ti+ikVPVaMCejzBIuUxrzG4VLhChCSJQw=";
     };
   
     patches = [
  
positive.code: , fetchFromGitHub
  , bash
  , cmake
  , flex
  , libclang
  , llvm
  
negative.code:     unifdef
    ];
  
    disabledTests = [
      # Needs gcc, fails when run noninteractively (without tty).
      "test_simple_reduction"
  