main.query_cache_innodb failed in buildbot (sporadic)

main.query_cache_innodb 'innodb'         w2 [ fail ]

        Test ended at 2017-09-08 00:44:13

CURRENT_TEST: main.query_cache_innodb

--- D:/win32-debug/build/src/mysql-test/r/query_cache_innodb.result	2017-09-07 23:50:38.990753900 +0000

+++ D:\win32-debug\build\src\mysql-test\r\query_cache_innodb.reject	2017-09-08 00:44:13.249526400 +0000

@@ -84,7 +84,7 @@

 use test;

 drop database `#mysql50#-`;

 SET NAMES default;

-FOUND 12 /\[ERROR\] Invalid \(old\?\) table or database name/ in mysqld.1.err

+FOUND 24 /\[ERROR\] Invalid \(old\?\) table or database name/ in mysqld.1.err

 set global query_cache_type=DEFAULT;

 set global query_cache_size=DEFAULT;

 End of 10.2 tests

mysqltest: Result content mismatch

 - saving 'D:/win32-debug/build/mysql-test/var/2/log/main.query_cache_innodb-innodb/' to 'D:/win32-debug/build/mysql-test/var/log/main.query_cache_innodb-innodb/'

Retrying test main.query_cache_innodb, attempt(2/3)...

***Warnings generated in error logs during shutdown after running tests: main.mysqlcheck main.query_cache_innodb main.join_cache main.function_defaults_innodb main.fast_prefix_index_fetch_innodb main.innodb_mrr_cpk main.insert_innodb main.progress_976225 main.innodb_utf8 main.innodb_mysql_lock

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name 't-1'

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name '-'

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name 't-2'

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name '-'

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name 't-1'

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name '-'

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name 't-2'

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name '-'

2017-09-08  0:44:12 2476 [ERROR] Invalid (old?) table or database name 't-2'

2017-09-08  0:44:13 2476 [ERROR] Invalid (old?) table or database name 't-1'

2017-09-08  0:44:13 2476 [ERROR] Invalid (old?) table or database name 't-2'