anchor.diff:  
     doCheck = true;
   
  +  passthru = {
  +    updateScript = nix-update-script {
  +      attrPath = finalAttrs.pname;
  +    };
  +    tests = {
  +      version = testers.testVersion {
  +        package = finalAttrs.finalPackage;
  +        command = "varlink --version";
  +      };
  +    };
  +  };
  +
     meta = with lib; {
       description = "C implementation of the Varlink protocol and command line tool";
       homepage = "https://github.com/varlink/libvarlink";
  
positive.code: , meson
  , ninja
  , python3
  }:
  
  stdenv.mkDerivation rec {
    pname = "libvarlink";
    version = "22";
  
    src = fetchFromGitHub {
      owner = "varlink";
      repo = pname;
      rev = version;
      sha256 = "1i15227vlc9k4276r833ndhxrcys9305pf6dga1j0alx2vj85yz2";
    };
  
    nativeBuildInputs = [ meson ninja ];
  
negative.code:     maintainers = with maintainers; [ artturin ];
      platforms = platforms.linux;
    };
  })
  