set @save_debug_dbug= @@debug_dbug;
set statement  debug_dbug="d,something" for select @@debug_dbug;
@@debug_dbug
d,something
set @@debug_dbug= @save_debug_dbug;
CREATE TABLE t1(f0 int auto_increment primary key, f1 int);
INSERT INTO t1(f1) VALUES (0),(1),(2),(3),(4),(5);
CALL mtr.add_suppression("Out of sort memory");
SET statement debug_dbug= '+d,alloc_sort_buffer_fail' for SELECT * FROM t1 ORDER BY f1 ASC, f0;
ERROR HY001: Out of sort memory, consider increasing server sort buffer size
SELECT * FROM t1 ORDER BY f1 ASC, f0;
f0	f1
1	0
2	1
3	2
4	3
5	4
6	5
DROP TABLE t1;
set @@debug_dbug= @save_debug_dbug;
set statement DEBUG_SYNC = 'now SIGNAL hi' for select 1;
ERROR 42000: The system variable debug_sync cannot be set in SET STATEMENT.