anchor.diff:  , srcRepo ? false, autoreconfHook ? null, texinfo ? null
   , siteStart ? ./site-start.el
   , nativeComp ? false
  +, withImageMagick ? lib.versionOlder version "27" && (withX || withNS)
   , toolkit ? (
     if withGTK2 then "gtk2"
     else if withGTK3 then "gtk3"
  
positive.code:              "--with-gif=no" "--with-tiff=no" ])
      ++ lib.optional withXwidgets "--with-xwidgets"
      ++ lib.optional nativeComp "--with-nativecomp"
      ;
  
    installTargets = [ "tags" "install" ];
  
negative.code:     ++ lib.optionals withX
        [ xlibsWrapper libXaw Xaw3d libXpm libpng libjpeg libungif libtiff libXft
          gconf cairo ]
      ++ 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 ]
  