anchor.diff:         Freetype `-I' cflags from being propagated. */ ''
         sed -i src/cairo.pc.in \
           -e 's|^Cflags:\(.*\)$|Cflags: \1 -I${freetype}/include/freetype2 -I${freetype}/include|g'
  -    '' + optionalString (xorg == null)
  +    '' + optionalString (!opengl-dummy.glx)
       /* tests and perf tools require Xorg */ ''
         sed -i Makefile.am \
           -e '/^SUBDIRS/ s#boilerplate test perf# #'
  
positive.code:     "--enable-interpreter"
      "--disable-symbol-lookup"
      #"--enable-some-floating-point"
      "--${boolwt opengl-dummy.glx}-x"
      #(wtFlag "skia" true "yes")
      #(wtFlag "skia-build-type" true "Release")
      "--without-gallium"
  
negative.code:   inherit (lib)
      boolEn
      boolWt
      optionals
      optionalString;
  in
  stdenv.mkDerivation rec {
  