5.7 mtr - incorrect thd::query string access causes assertion percona-server/include/thr_mutex.h:153: void safe_mutex_assert_not_owner(const my_mutex_t*): Assertion `!mp->count || !my_thread_equal(my_thread_self(), mp->thread)' failed.

rocksdb.rocksdb_deadlock_detect_rc
rocksdb.rocksdb_deadlock_detect_rr

5.7 added more protections around thd::query and compilations were fixed in at this commit https://github.com/percona/percona-server/commit/c601cb4079068788ad480df3b07aae3e81824c19

The problem is those changes do not account for cross thread access which now asserts like above. This typically happens when something like an i_s table is traversing/reporting queries from other threads. The fix is to properly use the new thd_query_safe function to access/copy the string.