encryption.innodb_encryption failed in buildbot, could not open connection 'default', got an error reading communication packets

encryption.innodb_encryption 'innodb,undo0' w1 [ fail ]  timeout after 900 seconds

        Test ended at 2017-12-05 01:03:54

Test case timeout after 900 seconds

== /usr/local/mariadb-10.3.3-linux-i686/mysql-test/var/1/log/innodb_encryption.log == 

NAME

innodb_system

SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;

NAME

# Success!

# Shutdown innodb_encryption_threads

SET GLOBAL innodb_encryption_threads=0;

# Turn on encryption

# since threads are off tables should remain unencrypted

SET GLOBAL innodb_encrypt_tables = on;

# Wait 15s to check that nothing gets encrypted

SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;

NAME

innodb_system

SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;

NAME

# Success!

# Startup innodb_encryption_threads

SET GLOBAL innodb_encryption_threads=@start_global_value;

# Wait max 10 min for key encryption threads to encrypt all spaces

 == /usr/local/mariadb-10.3.3-linux-i686/mysql-test/var/1/tmp/analyze-timeout-mysqld.1.err ==

mysqltest: Could not open connection 'default': 2013 Lost connection to MySQL server at 'handshake: reading inital communication packet', system error: 104

2017-12-05  1:00:29 9 [Note] InnoDB: Creating #1 encryption thread id 140174176548608 total threads 4.

2017-12-05  1:00:29 9 [Note] InnoDB: Creating #2 encryption thread id 140174151370496 total threads 4.

2017-12-05  1:00:29 9 [Note] InnoDB: Creating #3 encryption thread id 140174159763200 total threads 4.

2017-12-05  1:00:29 9 [Note] InnoDB: Creating #4 encryption thread id 140174142977792 total threads 4.

2017-12-05  1:05:22 9 [Warning] Aborted connection 9 to db: 'test' user: 'root' host: 'localhost' (Got an error reading communication packets)

171205  1:05:22 [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-log

key_buffer_size=1048576

read_buffer_size=131072

max_used_connections=1

max_threads=153

thread_count=7

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 63084 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/local/mariadb-10.3.3-linux-x86_64/bin/mysqld(my_print_stacktrace+0x2b)[0x7f7cfabf597b]

/usr/local/mariadb-10.3.3-linux-x86_64/bin/mysqld(handle_fatal_signal+0x4d7)[0x7f7cfa6b8cc7]

/lib/x86_64-linux-gnu/libpthread.so.0(+0xfcb0)[0x7f7cf90efcb0]

/lib/x86_64-linux-gnu/libc.so.6(__poll+0x53)[0x7f7cf880a303]

/usr/local/mariadb-10.3.3-linux-x86_64/bin/mysqld(_Z26handle_connections_socketsv+0x1ca)[0x7f7cfa478e2a]

/usr/local/mariadb-10.3.3-linux-x86_64/bin/mysqld(_Z11mysqld_mainiPPc+0x2a58)[0x7f7cfa47fa98]

/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7f7cf874376d]

/usr/local/mariadb-10.3.3-linux-x86_64/bin/mysqld(+0x50022d)[0x7f7cfa47422d]

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.