anchor.diff:    meta = with stdenv.lib; {
       homepage = "https://linphone.org/technical-corner/belle-sip";
       description = "Modern library implementing SIP (RFC 3261) transport, transaction and dialog layers";
  -    license = licenses.gpl3;
  +    license = licenses.gpl3Plus;
       platforms = platforms.all;
       maintainers = with maintainers; [ jluttine ];
     };
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "belle-sip";
    version = "4.4.13";
  
    src = fetchFromGitLab {
      domain = "gitlab.linphone.org";
  
negative.code:     group = "BC";
      repo = pname;
      rev = version;
      sha256 = "0ylv1jsqnfhw23i6p3lfqqzw48lwii8zwkq3y34q0hhnngn26iiw";
    };
  
    nativeBuildInputs = [ antlr3_4 cmake ];
  
    buildInputs = [ zlib ];
  
  