=== src/packfile.c
==================================================================
--- src/packfile.c	(revision 20000)
+++ src/packfile.c	(local)
@@ -1679,7 +1679,8 @@
 
         if ((size_t)(ret - cursor) != size) {
             internal_exception(1, "directory_pack segment '%s' used size %d "
-                "but reported %d\n", seg->name, (int)(ret-cursor), (int)size);
+                "but reported %d\n  (Ret: %d, Cursor: %d)\n",
+                seg->name, (int)(ret-cursor), (int)size), ret, cursor;
         }
         cursor = ret;
     }