This is not easily reproducible.

I noticed there is a typo in the error log:

2017-08-14 10:57:07 140082647533376 [ERROR] RocksDB: Can't enable both use_direct_io_for_flush_and_compaction use_direct_io_for_flush_and_compaction and allow_mmap_writes

but it cant' cause this issue, can it...

The issue comes from these lines in use_direct_reads_writes.test

--exec echo "restart:--rocksdb_use_direct_io_for_flush_and_compaction=1 --rocksdb_allow_mmap_writes=1" >$_expect_file_name

--sleep 0.1

--exec echo "restart:" >$_expect_file_name

MTR's check_expected_crash_and_restart function is invoked whenever mysqld process crashes or exits.

• if mysqld.expect file is not present, then this is considered to be a test failure
• if mysqld.expect file is present, it has commands to either wait or restart the server
• * in either case, .expect file is deleted after MTR has read the command from it.

In order to start the server with invalid arguments, use_direct_reads_writes.test puts them into .expect file and then it MUST be able to provide another .expect file.
This must happen

• after MTR has read and deleted the first file
• before the server has exited and MTR started to look what to do about this.

sleep 0.1 achieves this most of the time but this is still a race condition.