anchor.diff:  , gtk-doc
   , docbook-xsl-nons
   , docbook_xml_dtd_43
  +, docutils
   , gobject-introspection
   , gst_all_1
   , sofia_sip
  
positive.code:     gtk-doc
      docbook-xsl-nons
      docbook_xml_dtd_43
    ];
  
    buildInputs = [
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "calls";
    version = "43.0";
  
    src = fetchFromGitLab {
      domain = "gitlab.gnome.org";
      owner = "GNOME";
      repo = pname;
      rev = "v${version}";
      fetchSubmodules = true;
      hash = "sha256-fvG9N6HuuO8BMH8MJRquMSe1oEPNmX/pzsJX5yzs1CY=";
    };
  
    outputs = [ "out" "devdoc" ];
  