wsrep.variables test failed

failed for RHEL6:

wsrep.variables w1 [ fail ]
Test ended at 2019-12-18 22:57:12

CURRENT_TEST: wsrep.variables
— /__w/1/s/mysql-test/suite/wsrep/r/variables.result 2019-12-18 20:05:12.000000000 -0500
+++ /__w/1/s/mysql-test/suite/wsrep/r/variables.reject 2019-12-18 22:57:12.417041090 -0500
@@ -140,7 +140,7 @@
1
SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_rollbacker_thread_count';
VARIABLE_VALUE
-1
+0
SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_thread_count';
VARIABLE_VALUE
2

mysqltest: Result content mismatch

• saving '/var/tmp/mtr/1/log/wsrep.variables/' to '/var/tmp/mtr/log/wsrep.variables/'