anchor.diff:  { stdenv, fetchurl, makeFontsConf, makeWrapper
   , cairo, coreutils, fontconfig, freefont_ttf
  -, glib, gmp, gtk2, libedit, libffi, libjpeg
  +, glib, gmp, gtk3, libedit, libffi, libjpeg
   , libpng, libtool, mpfr, openssl, pango, poppler
   , readline, sqlite
   , disableDocs ? false
   , CoreFoundation
  +, gsettings_desktop_schemas
   }:
   
   let
  
positive.code:     fontconfig
      glib
      gmp
      gtk2
      libedit
      libjpeg
      libpng
  
negative.code: 
    postInstall = ''
      for p in $(ls $out/bin/) ; do
        wrapProgram $out/bin/$p \
          --prefix LD_LIBRARY_PATH ":" "${LD_LIBRARY_PATH}" \
          --prefix XDG_DATA_DIRS ":" "$GSETTINGS_SCHEMAS_PATH";
      done
    '';
  
  