anchor.diff:      ++ lib.optionals withX
         [ xlibsWrapper libXaw Xaw3d libXpm libpng libjpeg libungif libtiff libXft
           gconf cairo ]
  -    ++ lib.optionals (withX || withNS) [ imagemagick librsvg ]
  +    ++ lib.optionals (withX || withNS) [ librsvg ]
  +    ++ lib.optionals withImageMagick [ imagemagick ]
       ++ lib.optionals (stdenv.isLinux && withX) [ m17n_lib libotf ]
       ++ lib.optional (withX && withGTK2) gtk2-x11
       ++ lib.optionals (withX && withGTK3) [ gtk3-x11 gsettings-desktop-schemas ]
  
positive.code: , srcRepo ? false, autoreconfHook ? null, texinfo ? null
  , siteStart ? ./site-start.el
  , nativeComp ? false
  , toolkit ? (
    if withGTK2 then "gtk2"
    else if withGTK3 then "gtk3"
  
negative.code:              "--with-gif=no" "--with-tiff=no" ])
      ++ lib.optional withXwidgets "--with-xwidgets"
      ++ lib.optional nativeComp "--with-nativecomp"
      ++ lib.optional withImageMagick "--with-imagemagick"
      ;
  
    installTargets = [ "tags" "install" ];
  