Replication/hot_standby crashed in txn_limbo sometimes

[Gerold103]

Here is a failed job: https://travis-ci.org/github/tarantool/tarantool/jobs/706833309.

[007] replication/hot_standby.test.lua                                
[007] [Instance "hot_standby"] Tarantool server failed to start
[007] 
[007] Last 15 lines of Tarantool Log file [Instance "hot_standby"][/tarantool/test/var/007_replication/hot_standby.log]:
[007] 2020-07-10 11:06:36.544 [32490] main/103/hot_standby I> mapping 134217728 bytes for vinyl tuple arena...
[007] 2020-07-10 11:06:36.559 [32490] main/103/hot_standby I> instance uuid f0967d71-d838-4964-a6e1-12725f9a2283
[007] 2020-07-10 11:06:36.581 [32490] main/103/hot_standby I> instance vclock {0: 1023, 1: 1600, 2: 1}
[007] 2020-07-10 11:06:36.584 [32490] main/103/hot_standby I> recovery start
[007] 2020-07-10 11:06:36.584 [32490] main/103/hot_standby I> recovering from `master/00000000000000000040.snap'
[007] 2020-07-10 11:06:36.607 [32490] main/103/hot_standby I> cluster uuid 0b4051f2-5a9d-4a07-b51d-bddd52ce30d8
[007] 2020-07-10 11:06:36.636 [32490] main/103/hot_standby I> assigned id 1 to replica f0967d71-d838-4964-a6e1-12725f9a2283
[007] 2020-07-10 11:06:36.636 [32490] main/103/hot_standby I> recover from `master/00000000000000000040.xlog'
[007] 2020-07-10 11:06:36.637 [32490] main/103/hot_standby I> assigned id 2 to replica 67382cb7-e363-4fa3-b483-53a5cffc632b
[007] 2020-07-10 11:06:36.637 [32490] main/103/hot_standby I> removed replica 67382cb7-e363-4fa3-b483-53a5cffc632b
[007] 2020-07-10 11:06:36.639 [32490] main/103/hot_standby I> assigned id 2 to replica 21098aa9-820c-45de-84b5-3c199e75a22b
[007] 2020-07-10 11:06:36.639 [32490] main/103/hot_standby I> removed replica 21098aa9-820c-45de-84b5-3c199e75a22b
[007] 2020-07-10 11:06:36.640 [32490] main/103/hot_standby I> assigned id 2 to replica 1f95dc56-cbbe-43a0-b341-5488ba61a57f
[007] 2020-07-10 11:06:36.640 [32490] main/103/hot_standby I> removed replica 1f95dc56-cbbe-43a0-b341-5488ba61a57f
[007] tarantool: /tarantool/src/box/txn_limbo.c:117: txn_limbo_assign_remote_lsn: Assertion `limbo->instance_id != instance_id'

The test does not use sync transactions at all. What makes me think it may be just some not initialized memory.

[Gerold103]

box.cfg{}
s = box.schema.space.create('sync', {is_sync=true})
_ = s:create_index('pk')
s:replace{1}

Now restart and call box.cfg{} again.