anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "calls";
  -  version = "unstable-2019-10-29";
  +  version = "0.1.1";
   
     src = fetchFromGitLab {
       domain = "source.puri.sm";
       owner = "Librem5";
       repo = "calls";
  -    rev = "9fe575053d8f01c3a76a6c20d39f0816166d5afd";
  +    rev = "v${version}";
       sha256 = "01inx4mvrzvklwrfryw5hw9p89v8cn78m3qmv97g7a3v0h5c0n35";
     };
   
  
positive.code:     pkgconfig
      desktop-file-utils
      vala
    ];
  
    buildInputs = [
  
negative.code: , libpeas
  , dbus
  , vala
  , wrapGAppsHook
  , xorg
  , xvfb_run
  , libxml2
  