updated for version 7.4.609
Problem:    For complicated list and dict use the garbage collector can run
            out of stack space.
Solution:   Use a stack of dicts and lists to be marked, thus making it
            iterative instead of recursive. (Ben Fritz)
diff --git a/src/if_python3.c b/src/if_python3.c
index 374641d..300c24f 100644
--- a/src/if_python3.c
+++ b/src/if_python3.c
@@ -1649,8 +1649,8 @@
     }
 }
 
-    void
+    int
 set_ref_in_python3 (int copyID)
 {
-    set_ref_in_py(copyID);
+    int set_ref_in_py(copyID);
 }