Problem found during RQG testing. Valid for debug but also non debug builds.

.... 

2019-08-21 21:59:48 139863730599424 [Note] 10.2/bld_fast//sql/mysqld: ready for connections.

Version: '10.2.27-MariaDB-log'  socket:  ... port: 29020  Source distribution

190821 21:59:59 [ERROR] mysqld got signal 11 ;

...

    There is no query mentioned at all.

Thread 1 (Thread 0x7f342a7fc700 (LWP 265625)):

#0  my_read (Filedes=Filedes@entry=90, Buffer=Buffer@entry=0x7f342a7f9930 "Limit", ' ' <repeats 21 times>, "Soft Limit", ' ' <repeats 11 times>, "Hard Limit", ' ' <repeats 11 times>, "Units     \nMax cpu time", ' ' <repeats 14 times>, "unlimited", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "seconds   \nMax file size", ' ' <repeats 13 times>, "unlimited", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "bytes     \nMax data size", ' ' <repeats 13 times>, "unlimited", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "bytes     \nMax stack size", ' ' <repeats 12 times>, "8388608", ' ' <repeats 14 times>, "unlimited", ' ' <repeats 12 times>, "bytes     \nMax core file size        unlimited", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "bytes     \nMax resident set          unlimited", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "bytes     \nMax processes", ' ' <repeats 13 times>, "768201", ' ' <repeats 15 times>, "768201", ' ' <repeats 15 times>, "processes \nMax open files", ' ' <repeats 12 times>, "40960", ' ' <repeats 16 times>, "1048576", ' ' <repeats 14 times>, "files     \nMax locked memory         65536", ' ' <repeats 16 times>, "65536", ' ' <repeats 16 times>, "bytes     \nMax address space         unlimited", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "bytes     \nMax file locks", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "locks     \nMax pending signals       768201", ' ' <repeats 15 times>, "768201", ' ' <repeats 15 times>, "signals   \nMax msgqueue size         819200", ' ' <repeats 15 times>, "819200", ' ' <repeats 15 times>, "bytes     \nMax nice priority         0", ' ' <repeats 20 times>, "0", ' ' <repeats 20 times>, "\nMax realtime priority     0", ' ' <repeats 20 times>, "0", ' ' <repeats 20 times>, "\nMax realtime timeout      unlimited", ' ' <repeats 12 times>, "unlimited", ' ' <repeats 12 times>, "us        \n", Count=Count@entry=4096, MyFlags=MyFlags@entry=0) at mysys/my_read.c:63

#1  0x0000557a40400584 in output_core_info () at sql/signal_handler.cc:66

#2  0x0000557a404008f3 in handle_fatal_signal (sig=11) at sql/signal_handler.cc:339

#3  <signal handler called>

#4  fil_system_t::keyrotate_next (this=<optimized out>, prev_space=0x0, recheck=recheck@entry=true, key_version=key_version@entry=0) at storage/innobase/fil/fil0fil.cc:6025

#5  0x0000557a4075b694 in fil_crypt_find_space_to_rotate (recheck=<optimized out>, state=<optimized out>, key_state=<optimized out>) at storage/innobase/fil/fil0crypt.cc:1472

#6  fil_crypt_thread () at storage/innobase/fil/fil0crypt.cc:2183

#7  0x00007f348e8b06da in start_thread (arg=0x7f342a7fc700) at pthread_create.c:456

#8  0x00007f348dd42d7f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105

MDEV-20399 -- The protocol of my RQG run against 10.2 commit 6c06defb5f6ddccba1a3d7b03ba34dbb83c7ef69 2019-08-19 compiled without debug.

MDEV-20399.yy -- Simplified RQG grammar

MDEV-20399.cfg - Config file for replaying the problem with rqg_batch.pl

MDEV-20399.sh - Shellscript doing the replay

      The call is ./MDEV-20399.sh MDEV-20399.cfg <Binaries>

 RQG "expects" to find the required plugins like file_key_management.so in <Binaries>/lib/plugin/

The test is capable to replay also

     https://jira.mariadb.org/browse/MDEV-17596

     ... Assertion `block->page.flush_observer == __null || block->page.flush_observer == observer' failed in buf_flush_note_modification ... 

It replays MDEV-17596 far way more frequent than MDEV-20399.