We do not need gtk-doc on the target (and hopefully not in staging.. )

package/libglib2/libglib2.mk

@@ -45,6 +45,7 @@ LIBGLIB2_CONF_ENV =	\
 		gt_cv_c_wchar_t=$(if $(BR2_USE_WCHAR),yes,no)
 
 LIBGLIB2_CONF_OPT = --enable-shared \
+		--disable-gtk-doc \
 		--enable-static
 
 LIBGLIB2_DEPENDENCIES = uclibc gettext libintl pkgconfig