anchor.diff:    stdenv.mkDerivation rec {
       name = "signal-desktop-${version}";
   
  -    version = "1.11.0";
  +    version = "1.12.0";
   
       src =
         if stdenv.system == "x86_64-linux" then
           fetchurl {
             url = "https://updates.signal.org/desktop/apt/pool/main/s/signal-desktop/signal-desktop_${version}_amd64.deb";
  -          sha256 = "0s3qlzm7iy9qxca2hlh1hq0dnjr7y5wxad1ssqgmyhxsif0nqm96";
  +          sha256 = "19c9pilx2qkpyqw3p167bfcizrpd4np5jxdcwqmpbcfibmrpmcsk";
           }
         else
           throw "Signal for Desktop is not currently supported on ${stdenv.system}";
  
positive.code:     gdk_pixbuf
      glib
      gnome3.gconf
      gtk2
      pango
      libX11
      libXScrnSaver
  
negative.code: { stdenv, lib, fetchurl, dpkg, gnome3, gtk3, atk, cairo, pango, gdk_pixbuf, glib, freetype,
  fontconfig, dbus, libX11, xorg, libXi, libXcursor, libXdamage, libXrandr,
  libXcomposite, libXext, libXfixes, libXrender, libXtst, libXScrnSaver, nss,
  nspr, alsaLib, cups, expat, udev
  