anchor.diff: -{ lib, stdenv, fetchFromGitHub
  -, meson, ninja, pkg-config, makeWrapper
  -, gdk-pixbuf, libwebp
  +{ lib
  +, stdenv
  +, fetchFromGitHub
  +, meson
  +, ninja
  +, pkg-config
  +, makeWrapper
  +, gdk-pixbuf
  +, libwebp
   }:
  +
   let
  -  moduleDir = gdk-pixbuf.moduleDir;
  +  inherit (gdk-pixbuf) moduleDir;
   
     # turning lib/gdk-pixbuf-#.#/#.#.#/loaders into lib/gdk-pixbuf-#.#/#.#.#/loaders.cache
     # removeSuffix is just in case moduleDir gets a trailing slash
  
positive.code:     homepage = "https://github.com/aruiz/webp-pixbuf-loader";
      license = licenses.lgpl2Plus;
      platforms = platforms.unix;
      maintainers = [ maintainers.cwyc ];
      # meson.build:16:0: ERROR: Program or command 'gcc' not found or not executable
      broken = stdenv.isDarwin;
    };
  
negative.code: 
    src = fetchFromGitHub {
      owner = "aruiz";
      repo = "webp-pixbuf-loader";
      rev = version;
      sha256 = "sha256-dcdydWYrXZJjo4FxJtvzGzrQLOs87/BmxshFZwsT2ws=";
    };
  
    nativeBuildInputs = [
      gdk-pixbuf
      meson
      ninja
      pkg-config
      makeWrapper
    ];
  
    buildInputs = [
      gdk-pixbuf
      libwebp
    ];
  
    mesonFlags = [
      "-Dgdk_pixbuf_query_loaders_path=${gdk-pixbuf.dev}/bin/gdk-pixbuf-query-loaders"
      "-Dgdk_pixbuf_moduledir=${placeholder "out"}/${moduleDir}"
    ];
  
    postPatch = ''
      # It looks for gdk-pixbuf-thumbnailer in this package's bin rather than the gdk-pixbuf bin. We need to patch that.
      substituteInPlace webp-pixbuf.thumbnailer.in \
        --replace "@bindir@/gdk-pixbuf-thumbnailer" "$out/bin/webp-thumbnailer"
    '';
  
    preInstall = ''
      # environment variables controlling loaders.cache generation by gdk-pixbuf-query-loaders
      export GDK_PIXBUF_MODULE_FILE="$out/${loadersPath}"
      export GDK_PIXBUF_MODULEDIR="$out/${moduleDir}"
    '';
  
    postInstall = ''
      # It assumes gdk-pixbuf-thumbnailer can find the webp loader in the loaders.cache referenced by environment variable, breaking containment.
      # So we replace it with a wrapped executable.
      mkdir -p "$out/bin"
      makeWrapper "${gdk-pixbuf}/bin/gdk-pixbuf-thumbnailer" "$out/bin/webp-thumbnailer" \
        --set GDK_PIXBUF_MODULE_FILE "$out/${loadersPath}"
    '';
  
    meta = with lib; {
  