May not be the right way to do it but I just don't want those docs.

package/cairo/cairo.mk

@@ -41,11 +41,15 @@ CAIRO_CONF_ENV = ac_cv_func_posix_getpwuid_r=yes glib_cv_stack_grows=no \
 		ac_use_included_regex=no gl_cv_c_restrict=no \
 		ac_cv_path_GLIB_GENMARSHAL=$(HOST_GLIB)/bin/glib-genmarshal
 
+CAIRO_CONF_OPT = --disable-gtk-doc --with-html-dir=/dev/null
+
 ifeq ($(BR2_PACKAGE_DIRECTFB),y)
-	CAIRO_CONF_OPT = --disable-xlib --without-x --enable-directfb
+	CAIRO_CONF_OPT = --disable-xlib --without-x --enable-directfb \
+		--disable-gtk-doc --with-html-dir=/dev/null
 	CAIRO_DEPENDENCIES_EXTRA = directfb
 endif
 
+
 CAIRO_DEPENDENCIES = uclibc gettext libintl pkgconfig libglib2 zlib libpng fontconfig $(CAIRO_DEPENDENCIES_EXTRA) pixman $(XSERVER) 
 
 $(eval $(call AUTOTARGETS,package,cairo))

package/libglib2/libglib2.mk

@@ -45,7 +45,8 @@ LIBGLIB2_CONF_ENV =	\
 		gt_cv_c_wchar_t=$(if $(BR2_USE_WCHAR),yes,no)
 
 LIBGLIB2_CONF_OPT = --enable-shared \
-		--disable-gtk-doc \
+	 	--disable-gtk-doc \
+		--with-html-dir=/dev/null \
 		--enable-static
 
 LIBGLIB2_DEPENDENCIES = uclibc gettext libintl pkgconfig