--- stp-2.3.3/tools/rewrite_rule_gen/rewrite_rule_gen.cpp.orig	2017-11-16 15:35:07.000000000 -0700
+++ stp-2.3.3/tools/rewrite_rule_gen/rewrite_rule_gen.cpp	2017-11-25 08:42:45.331112638 -0700
@@ -1223,7 +1223,7 @@ void rule_to_string(const ASTNode& n, AS
   for (size_t i = 0; i < n.Degree(); i++)
   {
     char t[1000];
-    sprintf(t, "%s[%d]", current.c_str(), i);
+    sprintf(t, "%s[%zu]", current.c_str(), i);
     string s(t);
     rule_to_string(n[i], names, s, sofar);
   }
@@ -1242,7 +1242,7 @@ string containsNode(const ASTNode& n, co
   for (size_t i = 0; i < n.Degree(); i++)
   {
     char t[1000];
-    sprintf(t, "%s[%d]", current.c_str(), i);
+    sprintf(t, "%s[%zu]", current.c_str(), i);
     string s(t);
     string r = containsNode(n[i], hunting, s);
     if (r != "")