anchor.diff:  , libnotify
   , libpulseaudio
   , libuuid
  +, libxshmfence
   , mesa
   , nspr
   , nss
  
positive.code:     libnotify
      libuuid
      libxcb
      mesa
      nspr
      nss
  
negative.code: in stdenv.mkDerivation rec {
  
    pname = "opera";
    version = "76.0.4017.94";
  
    src = fetchurl {
      url = "${mirror}/${version}/linux/${pname}-stable_${version}_amd64.deb";
      sha256 = "sha256-vjSfzkl1jIQ9P1ARDa0eOuD8CmKHIEZ+IwMB2wIVjE8=";
    };
  
    unpackCmd = "${dpkg}/bin/dpkg-deb -x $curSrc .";
  