anchor.diff:  }:
   { stdenv, lib, fetchurl, fetchpatch, ncurses, xlibsWrapper, libXaw, libXpm
   , Xaw3d, libXcursor,  pkg-config, gettext, libXft, dbus, libpng, libjpeg, giflib
  -, libtiff, librsvg, gconf, libxml2, imagemagick, gnutls, libselinux
  +, libtiff, librsvg, libwebp, gconf, libxml2, imagemagick, gnutls, libselinux
   , alsa-lib, cairo, acl, gpm, AppKit, GSS, ImageIO, m17n_lib, libotf
   , sigtool, jansson, harfbuzz, sqlite, nixosTests
   , dontRecurseIntoAttrs, emacsPackagesFor
  
positive.code:     ++ lib.optionals (withX && withGTK3) [ gtk3-x11 gsettings-desktop-schemas ]
      ++ lib.optional (withX && withMotif) motif
      ++ lib.optional withSQLite3 sqlite
      ++ lib.optionals (withX && withXwidgets) [ webkitgtk glib-networking ]
      ++ lib.optionals withNS [ AppKit GSS ImageIO ]
      ++ lib.optionals stdenv.isDarwin [ sigtool ]
  
negative.code: , withMotif ? false, motif ? null
  , withSQLite3 ? false
  , withCsrc ? true
  , withWebP ? false
  , srcRepo ? false, autoreconfHook ? null, texinfo ? null
  , siteStart ? ./site-start.el
  , nativeComp ? false
  