test: flaky replication/autobootstrap_guest.test.lua test breaks test-run

[avtikhon]

Tarantool version:
| Tarantool 2.7.0-84-g6225d7fe4
| Target: Darwin-x86_64-RelWithDebInfo
| Build options: cmake . -DCMAKE_INSTALL_PREFIX=/Users/tntmac03.tarantool.i/builds/6KMaH8fQ/0/tarantool/tarantool/static-build/tarantool-prefix -DENABLE_BACKTRACE=TRUE
| Compiler: /Library/Developer/CommandLineTools/usr/bin/cc /Library/Developer/CommandLineTools/usr/bin/c++
| C_FLAGS: -Wno-unknown-pragmas -fexceptions -funwind-tables -fno-omit-frame-pointer -fno-stack-protector -fno-common -msse2 -std=c11 -Wall -Wextra -Wno-strict-aliasing -Wno-char-subscripts -Wno-gnu-alignof-expression -Werror
| CXX_FLAGS: -Wno-unknown-pragmas -fexceptions -funwind-tables -fno-omit-frame-pointer -fno-stack-protector -fno-common -msse2 -std=c++11 -Wall -Wextra -Wno-strict-aliasing -Wno-char-subscripts -Wno-invalid-offsetof -Wno-gnu-alignof-expression -Werror

OS version:
OSX 15

Bug description:
https://gitlab.com/tarantool/tarantool/-/jobs/877795556#L6449

artifacts.zip

Parsing 'log/086_replication.log' file found:

1. Test started at:
   [2020-11-28 00:24:42.883310] replication/autobootstrap_guest.test.lua

2. The issue happened on test-run command:
   [2020-11-28 00:24:46.508512] DEBUG: sending command: test_run:wait_fullmesh(SERVERS)

3. The issue shown in log:

[2020-11-28 00:24:46.509198] DEBUG: test-run received command: eval autobootstrap_guest1 "return box.info.server"
[2020-11-28 00:24:46.518993] DEBUG: test-run's response for [eval autobootstrap_guest1 "return box.info.server"]
[2020-11-28 00:24:46.518993]  | - id: 1
[2020-11-28 00:24:46.518993]  |   lsn: 0
[2020-11-28 00:24:46.518993]  |   ro: true
[2020-11-28 00:24:46.518993]  |   uuid: 1567c295-bbaa-49b1-88e2-512b81226324
[2020-11-28 00:24:46.518993]  | ...
[2020-11-28 00:24:46.519735] DEBUG: test-run received command: eval autobootstrap_guest2 "box.info.replication[1]"
[2020-11-28 00:24:46.521056] DEBUG: test-run's response for [eval autobootstrap_guest2 "box.info.replication[1]"]
[2020-11-28 00:24:46.521056]  | - null
[2020-11-28 00:24:46.521056]  | ...
[2020-11-28 00:24:46.523623] DEBUG: test-run received command: config engine
[2020-11-28 00:24:46.524075] DEBUG: test-run's response for [config engine]
[2020-11-28 00:24:46.524075]  | !!python/unicode 'engine': !!python/unicode 'vinyl'
[2020-11-28 00:24:46.524075]  | ...
[2020-11-28 00:24:46.576851] DEBUG: test-run received command: eval autobootstrap_guest2 "box.info.replication[1]"
[2020-11-28 00:24:46.579123] 
[2020-11-28 00:24:46.579123] TarantoolInpector.handle() received the following error:
[2020-11-28 00:24:46.579123] Traceback (most recent call last):
[2020-11-28 00:24:46.579123]   File "/Users/tntmac03.tarantool.i/builds/6KMaH8fQ/0/tarantool/tarantool/test-run/lib/inspector.py", line 100, in handle
[2020-11-28 00:24:46.579123]     result = self.parser.parse_preprocessor(line)
[2020-11-28 00:24:46.579123]   File "/Users/tntmac03.tarantool.i/builds/6KMaH8fQ/0/tarantool/tarantool/test-run/lib/preprocessor.py", line 87, in parse_preprocessor
[2020-11-28 00:24:46.579123]     return self.lua_eval(name, expr[1:-1])
[2020-11-28 00:24:46.579123]   File "/Users/tntmac03.tarantool.i/builds/6KMaH8fQ/0/tarantool/tarantool/test-run/lib/preprocessor.py", line 404, in lua_eval
[2020-11-28 00:24:46.579123]     result = yaml.safe_load(result)
[2020-11-28 00:24:46.579123]   File "/usr/local/lib/python2.7/site-packages/yaml/__init__.py", line 162, in safe_load
[2020-11-28 00:24:46.579123]     return load(stream, SafeLoader)
[2020-11-28 00:24:46.579123]   File "/usr/local/lib/python2.7/site-packages/yaml/__init__.py", line 112, in load
[2020-11-28 00:24:46.579123]     loader = Loader(stream)
[2020-11-28 00:24:46.579123]   File "/usr/local/lib/python2.7/site-packages/yaml/loader.py", line 34, in __init__
[2020-11-28 00:24:46.579123]     Reader.__init__(self, stream)
[2020-11-28 00:24:46.579123]   File "/usr/local/lib/python2.7/site-packages/yaml/reader.py", line 87, in __init__
[2020-11-28 00:24:46.579123]     self.determine_encoding()
[2020-11-28 00:24:46.579123]   File "/usr/local/lib/python2.7/site-packages/yaml/reader.py", line 126, in determine_encoding
[2020-11-28 00:24:46.579123]     self.update_raw()
[2020-11-28 00:24:46.579123]   File "/usr/local/lib/python2.7/site-packages/yaml/reader.py", line 183, in update_raw
[2020-11-28 00:24:46.579123]     data = self.stream.read(size)
[2020-11-28 00:24:46.579123] AttributeError: 'NoneType' object has no attribute 'read'
[2020-11-28 00:24:46.579594] DEBUG: test-run's response for [eval autobootstrap_guest2 "box.info.replication[1]"]
[2020-11-28 00:24:46.579594]  | error: AttributeError("'NoneType' object has no attribute 'read'",)
[2020-11-28 00:24:46.579594]  | ...
[2020-11-28 00:24:46.579866] Kill all servers ...
[2020-11-28 00:24:46.749129] 
[2020-11-28 00:24:46.749129] 
[2020-11-28 00:24:46.749129] [Instance "autobootstrap_guest2" returns with non-zero exit code: 1]

4. The issue happened inside test_run:wait_fullmesh() routine on replica information evaluation:

local wait_fullmesh_cmd = 'box.info.replication[%s]'

local function wait_fullmesh(self, servers)
...
                    local cmd = wait_fullmesh_cmd:format(server_id)
                    local info = self:eval(server2, cmd)[1]

Steps to reproduce:

Optional (but very desirable):

• coredump
• backtrace
• netstat