freebsd-ports/textproc/libxml2/files/patch-config.h.in

--- config.h.in.orig	2018-03-05 15:54:17 UTC
+++ config.h.in
@@ -1,5 +1,8 @@
 /* config.h.in.  Generated from configure.ac by autoheader.  */
 
+/* XXX */
+#define HAVE_VFSCANF
+
 /* Type cast for the gethostbyname() argument */
 #undef GETHOSTBYNAME_ARG_CAST