anchor.diff:  # be nice to add the native GUI (and/or the GTK GUI) as an option too, but that
   # requires invoking the Xcode build system, which is non-trivial for now.
   
  -{ stdenv, lib, fetchurl,
  +{ stdenv, lib, fetchFromGitHub,
     # Main build tools
     pkgconfig, autoconf, automake, libtool, m4, lzma, python3,
     numactl,
  
positive.code:     gst_all_1.gstreamer gst_all_1.gst-plugins-base dbus-glib udev
      libgudev hicolor-icon-theme
    ] ++ lib.optional useFdk fdk_aac
      ++ lib.optionals stdenv.isDarwin [ AudioToolbox Foundation libobjc VideoToolbox ]
    # NOTE: 2018-12-27: Handbrake supports nv-codec-headers for Linux only,
    # look at ./make/configure.py search "enable_nvenc"
      ++ lib.optional stdenv.isLinux nv-codec-headers;
  
    preConfigure = ''
      patchShebangs scripts
  
      substituteInPlace libhb/module.defs \
        --replace /usr/include/libxml2 ${libxml2.dev}/include/libxml2
  
      # Force using nixpkgs dependencies
      sed -i '/MODULES += contrib/d' make/include/main.defs
      sed -e 's/^[[:space:]]*\(meson\|ninja\|nasm\)[[:space:]]*= ToolProbe.*$//g' \
          -e '/    ## Additional library and tool checks/,/    ## MinGW specific library and tool checks/d' \
          -i make/configure.py
    '';
  
    configureFlags = [
      "--disable-df-fetch"
      "--disable-df-verify"
      (if useGtk          then "--disable-gtk-update-checks" else "--disable-gtk")
  
negative.code:   # for now we disable GTK GUI support on Darwin. (It may be possible to remove
    # this restriction later.)
    useGtk ? !stdenv.isDarwin, wrapGAppsHook ? null,
    intltool ? null,
    glib ? null,
    gtk3 ? null,
    libappindicator-gtk3 ? null,
    libnotify ? null,
    gst_all_1 ? null,
    dbus-glib ? null,
    udev ? null,
    libgudev ? null,
    hicolor-icon-theme ? null,
    # FDK
    useFdk ? false, fdk_aac ? null
  }:
  
  assert stdenv.isDarwin -> AudioToolbox != null
         && Foundation != null
         && libobjc != null
         && VideoToolbox != null;
  
  stdenv.mkDerivation rec {
    pname = "handbrake";
    version = "1.3.2";
  
    src = fetchFromGitHub {
      owner = "HandBrake";
      repo = "HandBrake";
      rev = version;
      sha256 = "04z3hcy7m5yvma849rlrsx2wdqmkilkl1qds9yrzr2ydpw697f85";
      extraPostFetch = ''
        echo "DATE=$(date +"%F %T %z" -r $out/NEWS.markdown)" > $out/version.txt
      '';
    };
  
    # we put as little as possible in src.extraPostFetch as it's much easier to
    # add to it here without having to fiddle with src.sha256
    # only DATE and HASH are absolutely necessary
    postPatch = ''
      cat >> version.txt <<_EOF
  HASH=${src.rev}
  SHORTHASH=${src.rev}
  TAG=${version}
  URL=${src.meta.homepage}
  _EOF
  
      patchShebangs scripts
  
      substituteInPlace libhb/module.defs \
        --replace /usr/include/libxml2 ${libxml2.dev}/include/libxml2
  
      # Force using nixpkgs dependencies
      sed -i '/MODULES += contrib/d' make/include/main.defs
      sed -e 's/^[[:space:]]*\(meson\|ninja\|nasm\)[[:space:]]*= ToolProbe.*$//g' \
          -e '/    ## Additional library and tool checks/,/    ## MinGW specific library and tool checks/d' \
          -i make/configure.py
    '';
  
    nativeBuildInputs = [
      pkgconfig autoconf automake libtool m4 python3
  