Crash in in Explain_node::print_explain_for_children while writing to the slow query log

210721 1:33:14 [ERROR] mysqld got signal 11 ;

This could be because you hit a bug. It is also possible that this binary

or one of the libraries it was linked against is corrupt, improperly built,

or misconfigured. This error can also be caused by malfunctioning hardware.

To report this bug, see https://mariadb.com/kb/en/reporting-bugs

We will try our best to scrape up some info that will hopefully help

diagnose the problem, but since we have already crashed,

something is definitely wrong and this may fail.

Server version: 10.3.22-MariaDB-log

key_buffer_size=33554432

read_buffer_size=2097152

max_used_connections=205

max_threads=65546

thread_count=28

It is possible that mysqld could use up to

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 402770140 K bytes of memory

Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x7f7d1cb5d4e8

Attempting backtrace. You can use the following information to find out

where mysqld died. If you see no messages after this, something went

terribly wrong...

stack_bottom = 0x7f86307edd58 thread_stack 0x49000

mysys/stacktrace.c:270(my_print_stacktrace)[0x7f865dddcc5b]

sql/signal_handler.cc:209(handle_fatal_signal)[0x7f865d880387]

/lib64/libpthread.so.0(+0x3de160f7e0)[0x7f865cc5e7e0]

sql/sql_explain.cc:640(Explain_node::print_explain_for_children(Explain_query*, select_result_sink*, unsigned char, bool))[0x7f865d7aac1c]

sql/sql_explain.cc:825(Explain_select::print_explain(Explain_query*, select_result_sink*, unsigned char, bool))[0x7f865d7afea6]

sql/sql_explain.cc:262(Explain_query::print_explain_str(THD*, String*, bool))[0x7f865d7aa9fe]

sql/log.cc:3075(MYSQL_QUERY_LOG::write(THD*, long, char const*, unsigned long, unsigned long long, unsigned long long, bool, char const*, unsigned long))[0x7f865d93e897]

sql/log.cc:1086(Log_to_file_event_handler::log_slow(THD*, my_hrtime_t, char const*, unsigned long, unsigned long long, unsigned long long, bool, char const*, unsigned long))[0x7f865d93ec80]

sql/log.cc:1358(LOGGER::slow_log_print(THD*, char const*, unsigned long, unsigned long long))[0x7f865d9399bd]

sql/sql_parse.cc:2559(log_slow_statement(THD*))[0x7f865d6b638f]

sql/sql_class.h:1825(dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool))[0x7f865d6c3de2]

sql/sql_parse.cc:1404(do_command(THD*))[0x7f865d6c560e]

sql/threadpool_common.cc:359(threadpool_process_request)[0x7f865d7c97c8]

sql/threadpool_generic.cc:1601(worker_main)[0x7f865d856438]

perfschema/pfs.cc:1872(pfs_spawn_thread)[0x7f865d9f90bd]

/lib64/libpthread.so.0(+0x3de1607aa1)[0x7f865cc56aa1]

/lib64/libc.so.6(clone+0x6d)[0x7f865bbd5aad]

Trying to get some variables.

Some pointers may be invalid and cause the dump to abort.

Query (0x7f7d1cb45a50): SELECT * FROM ( SELECT ...  FROM t WHERE ... GROUP BY c1, c2 ) tmp WHERE 1=0