ppc64le platform: rocksdb.drop_index_inplace failed in buildbot

CURRENT_TEST: rocksdb.drop_index_inplace

2017-10-27  0:17:29 64579 [Note] RocksDB: Manual memtable flush.

2017-10-27  0:17:29 0 [Note] /usr/sbin/mysqld (root[root] @ localhost []): Normal shutdown

2017-10-27  0:17:29 0 [Note] Event Scheduler: Purging the queue. 0 events

171027  0:18:29 [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: 10.3.3-MariaDB-10.3.3+maria~trusty-log

key_buffer_size=1048576

read_buffer_size=131072

max_used_connections=52

max_threads=153

thread_count=0

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 63035 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

/usr/sbin/mysqld(my_print_stacktrace+0x64)[0x45d42304]

/usr/sbin/mysqld(handle_fatal_signal+0x444)[0x4564df44]

[0x3fff834f0478]

/lib/powerpc64le-linux-gnu/libpthread.so.0(pthread_cond_wait+0x1a0)[0x3fff8310e710]

/lib/powerpc64le-linux-gnu/libpthread.so.0(pthread_cond_wait+0xa0)[0x3fff8310e610]

/usr/sbin/mysqld(_Z11mysqld_mainiPPc+0x33b0)[0x45354f40]

/usr/sbin/mysqld(main+0x20)[0x4532a910]

/lib/powerpc64le-linux-gnu/libc.so.6(+0x24d80)[0x3fff82cf4d80]

/lib/powerpc64le-linux-gnu/libc.so.6(__libc_start_main+0xc8)[0x3fff82cf4f78]

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.