anchor.diff:      gtk-doc
       docbook-xsl-nons
       docbook_xml_dtd_43
  +    docutils
     ];
   
     buildInputs = [
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "calls";
    version = "42.0";
  
    src = fetchFromGitLab {
      domain = "gitlab.gnome.org";
      owner = "GNOME";
      repo = pname;
      rev = version;
      fetchSubmodules = true;
      hash = "sha256-ASKK9PB5FAD10CR5O+L2WgMjCzmIalithHL8jV0USiM=";
    };
  
    outputs = [ "out" "devdoc" ];
  
negative.code: , gtk-doc
  , docbook-xsl-nons
  , docbook_xml_dtd_43
  , docutils
  , gobject-introspection
  , gst_all_1
  , sofia_sip
  