--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -2302,6 +2302,9 @@ build_target_command_list (struct bp_loc
 		 need to parse the command to bytecodes again.  */
 	      aexpr = parse_cmd_to_aexpr (bl->address,
 					  loc->owner->extra_string);
+	      if (aexpr == NULL)
+		error (_("Agent is not support commands of breakpoint %d."),
+		       bl->owner->number);
 	      loc->cmd_bytecode = aexpr;
 
 	      if (!aexpr)