Instance restart - after running mysql_upgrade script - produced following crash error.
Subsequent rstarts show a clean error log.

2018-01-10 12:19:24 0x7f35c80c8700 InnoDB: Assertion failure in file /home/buildbot/buildbot/build/storage/innobase/que/que0que.cc line 567
InnoDB: We intentionally generate a memory trap.
InnoDB: Submit a detailed bug report to https://jira.mariadb.org/
InnoDB: If you get repeated assertion failures or crashes, even
InnoDB: immediately after the mysqld startup, there may be
InnoDB: corruption in the InnoDB tablespace. Please refer to
InnoDB: http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html
InnoDB: about forcing recovery.
180110 12:19:24 [ERROR] mysqld got signal 6 ;
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: 10.2.12-MariaDB-log
key_buffer_size=268435456
read_buffer_size=131072
max_used_connections=5
max_threads=502
thread_count=0
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1365189 K bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x0
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 = 0x0 thread_stack 0x49000
/home/fds/ferdb/mysql/bin/mysqld(my_print_stacktrace+0x2e)[0xde610e]
/home/fds/ferdb/mysql/bin/mysqld(handle_fatal_signal+0x471)[0x7de601]
/lib64/libpthread.so.0[0x3d31e0f7e0]
/lib64/libc.so.6(gsignal+0x35)[0x3d31632495]
/lib64/libc.so.6(abort+0x175)[0x3d31633c75]
/home/fds/ferdb/mysql/bin/mysqld[0xbafc13]
/home/fds/ferdb/mysql/bin/mysqld[0xad7f63]
/home/fds/ferdb/mysql/bin/mysqld[0xb0e9e3]
/home/fds/ferdb/mysql/bin/mysqld[0xa2b73a]
/home/fds/ferdb/mysql/bin/mysqld(_Z8closefrmP5TABLE+0x11e)[0x6a811e]
/home/fds/ferdb/mysql/bin/mysqld(_Z8tc_purgeb+0x61)[0x769981]
/home/fds/ferdb/mysql/bin/mysqld(_Z19close_cached_tablesP3THDP10TABLE_LISTbm+0x87)[0x59fd17]
/home/fds/ferdb/mysql/bin/mysqld[0x547895]
/home/fds/ferdb/mysql/bin/mysqld(kill_server_thread+0xa3)[0x54e8c3]
/home/fds/ferdb/mysql/bin/mysqld[0xa054a9]
/lib64/libpthread.so.0[0x3d31e07aa1]
/lib64/libc.so.6(clone+0x6d)[0x3d316e8bcd]
The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
information that should help you find out what is causing the crash.