GLOBAL DEBUG variable does not work

mysql-test/r/rpl_incident.result

@@ -12,10 +12,7 @@ a
 1
 2
 3
-SET @saved = @@debug;
-SET GLOBAL debug="d,incident_database_resync_on_replace";
 REPLACE INTO t1 VALUES (4);
-SET GLOBAL debug=@saved;
 SELECT * FROM t1;
 a
 1

mysql-test/t/rpl_incident-master.opt

+--loose-debug=+d,incident_database_resync_on_replace

mysql-test/t/rpl_incident.test

@@ -7,13 +7,9 @@ CREATE TABLE t1 (a INT);
 INSERT INTO t1 VALUES (1),(2),(3);
 SELECT * FROM t1;
 
-SET @saved = @@debug;
-SET GLOBAL debug="d,incident_database_resync_on_replace";
-
 # This will generate an incident log event and store it in the binary
 # log before the replace statement.
 REPLACE INTO t1 VALUES (4);
-SET GLOBAL debug=@saved;
 --save_master_pos
 SELECT * FROM t1;