encryption.create_or_replace fails sporadically in buildbot: failing assertion: mutex->magic_n == MUTEX_MAGIC_N

2015-12-31  9:18:41 3001334592 [Note] InnoDB: Creating #1 thread id 2814376768 total threads 1.

2015-12-31 09:18:47 a7bffb40  InnoDB: Assertion failure in thread 2814376768 in file sync0sync.cc line 485

InnoDB: Failing assertion: mutex->magic_n == MUTEX_MAGIC_N

InnoDB: We intentionally generate a memory trap.

InnoDB: Submit a detailed bug report to http://bugs.mysql.com.

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/5.6/en/forcing-innodb-recovery.html

InnoDB: about forcing recovery.

151231  9:18:47 [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 http://kb.askmonty.org/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: 10.1.10-MariaDB-debug-log

key_buffer_size=1048576

read_buffer_size=131072

max_used_connections=1

max_threads=153

thread_count=1

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 61807 K  bytes of memory

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

Thread pointer: 0x0x0

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 0x48000

mysys/stacktrace.c:246(my_print_stacktrace)[0x8b04599]

sql/signal_handler.cc:160(handle_fatal_signal)[0x843561c]

[0xba0400]

[0xba0416]

/lib/i386-linux-gnu/libc.so.6(gsignal+0x4f)[0x1471ef]

/lib/i386-linux-gnu/libc.so.6(abort+0x175)[0x14a835]

sync/sync0sync.cc:485(mutex_validate(ib_mutex_t const*))[0x8846334]

include/sync0sync.ic:254(mutex_enter_func)[0x895d2ab]

/lib/i386-linux-gnu/libpthread.so.0(+0x6d4c)[0x337d4c]

/lib/i386-linux-gnu/libc.so.6(clone+0x5e)[0x203ace]

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.

Writing a core file