mariabackup.xb_file_key_management failed in buildbot with Failing assertion: byte_offset % OS_FILE_LOG_BLOCK_SIZE == 0

mariabackup.xb_file_key_management       w3 [ fail ]

        Test ended at 2018-02-01 21:05:11

CURRENT_TEST: mariabackup.xb_file_key_management

mysqltest: At line 22: exec of 'D:/winx64-debug/build/extra/mariabackup/Debug/mariabackup.exe  --prepare --target-dir=D:/winx64-debug/build/mysql-test/var/3/tmp/backup 2>&1' failed, error: 255, status: 255, errno: 2

Output from before failure:

D:/winx64-debug/build/extra/mariabackup/Debug/mariabackup.exe based on MariaDB server 10.2.13-MariaDB Win64 (AMD64) 

mariabackup: cd to D:/winx64-debug/build/mysql-test/var/3/tmp/backup/

Loading encryption plugin

	 Encryption plugin parameter :  '--file_key_management_encryption_algorithm=aes_cbc'

	 Encryption plugin parameter :  '--file_key_management_filekey=FILE:D:/winx64-debug/build/src/mysql-test/suite/mariabackup/filekeys-data.key'

	 Encryption plugin parameter :  '--file_key_management_filename=D:/winx64-debug/build/src/mysql-test/suite/mariabackup/filekeys-data.enc'

	 Encryption plugin parameter :  '--prepare'

	 Encryption plugin parameter :  '--target-dir=D:/winx64-debug/build/mysql-test/var/3/tmp/backup'

mariabackup: This target seems to be not prepared yet.

mariabackup: using the following InnoDB configuration for recovery:

mariabackup:   innodb_data_home_dir = .

mariabackup:   innodb_data_file_path = ibdata1:12M:autoextend

mariabackup:   innodb_log_group_home_dir = .

mariabackup: Starting InnoDB instance for recovery.

mariabackup: Using 104857600 bytes for buffer pool (set by --use-memory parameter)

2018-02-01 21:04:52 5332 [Note] InnoDB: !!!!!!!! UNIV_DEBUG switched on !!!!!!!!!

2018-02-01 21:04:52 5332 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions

2018-02-01 21:04:52 5332 [Note] InnoDB: Uses event mutexes

2018-02-01 21:04:52 5332 [Note] InnoDB: Compressed tables use zlib 1.2.3

2018-02-01 21:04:52 5332 [Note] InnoDB: Number of pools: 1

2018-02-01 21:04:52 5332 [Note] InnoDB: Using SSE2 crc32 instructions

2018-02-01 21:04:52 5332 [Note] InnoDB: Initializing buffer pool, total size = 100M, instances = 1, chunk size = 100M

2018-02-01 21:04:52 5332 [Note] InnoDB: Completed initialization of buffer pool

2018-02-01 21:04:52 5332 [Note] InnoDB: Highest supported file format is Barracuda.

2018-02-01 21:04:52 0x14d4  InnoDB: Assertion failure in file D:\winx64-debug\build\src\storage\innobase\fil\fil0fil.cc line 5272

InnoDB: Failing assertion: byte_offset % OS_FILE_LOG_BLOCK_SIZE == 0

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: https://mariadb.com/kb/en/library/xtradbinnodb-recovery-modes/

InnoDB: about forcing recovery.

180201 21:04:52 [ERROR] mysqld got exception 0x80000003 ;

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: 10.2.13-MariaDB-debug

key_buffer_size=0

read_buffer_size=131072

max_used_connections=0

max_threads=1

thread_count=0

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 4993 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...

mariabackup.exe!my_sigabrt_handler()[my_thr_init.c:488]

mariabackup.exe!raise()[signal.cpp:516]

mariabackup.exe!abort()[abort.cpp:71]

mariabackup.exe!ut_dbg_assertion_failed()[ut0dbg.cc:62]

mariabackup.exe!fil_io()[fil0fil.cc:5272]

mariabackup.exe!log_group_read_log_seg()[log0recv.cc:655]

mariabackup.exe!recv_group_scan_log_recs()[log0recv.cc:2996]

mariabackup.exe!recv_recovery_from_checkpoint_start()[log0recv.cc:3253]

mariabackup.exe!innobase_start_or_create_for_mysql()[srv0start.cc:2246]

mariabackup.exe!innodb_init()[xtrabackup.cc:1676]

mariabackup.exe!xtrabackup_prepare_func()[xtrabackup.cc:4844]

mariabackup.exe!main_low()[xtrabackup.cc:5523]

mariabackup.exe!main()[xtrabackup.cc:5320]

mariabackup.exe!__scrt_common_main_seh()[exe_common.inl:283]

KERNEL32.DLL!BaseThreadInitThunk()

ntdll.dll!RtlUserThreadStart()

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.

The result from queries just before the failure was:

CREATE TABLE t(c VARCHAR(10)) ENGINE INNODB encrypted=yes;

INSERT INTO t VALUES('foobar1');

# xtrabackup backup

NOT FOUND /foobar1/ in ib_logfile0

# expect NOT FOUND

INSERT INTO t VALUES('foobar2');

# xtrabackup prepare