anchor.diff:        --replace "@abs_top_builddir@" "$out"
     '';
   
  -  # Install mug
  -  postInstall = lib.optionalString withMug ''
  +  # Make sure included scripts can find their dependencies & optionally install mug
  +  postInstall = ''
  +    wrapProgram "$out/bin/mu" \
  +      --prefix LD_LIBRARY_PATH : "$out/lib" \
  +      --prefix GUILE_LOAD_PATH : "$out/share/guile/site/2.2"
  +  '' + lib.optionalString withMug ''
       for f in mug ; do
         install -m755 toys/$f/$f $out/bin/$f
       done
  
positive.code:     ++ lib.optional (!stdenv.isDarwin) guile
      ++ lib.optionals withMug [ gtk3 webkitgtk ];
  
    nativeBuildInputs = [ pkg-config autoreconfHook pmccabe ];
  
    enableParallelBuilding = true;
  
  
negative.code: { lib, stdenv, fetchFromGitHub, sqlite, pkg-config, autoreconfHook, pmccabe
  , xapian, glib, gmime3, texinfo, emacs, guile
  , gtk3, webkitgtk, libsoup, icu
  , makeWrapper
  , withMug ? false
  , batchSize ? null }:
  
  