Unexpected information in `luatest.assert_equals` after enabling some compat options

[ImeevMA]

Tarantool: 3.1+
Reproducer:
Create a following test:

local server = require('luatest.server')
local t = require('luatest')

local g = t.group()

g.before_all(function()
    g.server = server:new({alias = 'master'})
    g.server:start()
end)

g.after_all(function()
    g.server:stop()
end)

g.test_usual_error = function()
    g.server:exec(function()
        t.assert_equals(1, 2)
    end)
end

g.test_verbose_error = function()
    local compat = require('compat')
    compat.box_error_serialize_verbose = 'new'
    compat.box_error_unpack_type_and_code = 'new'
    g.server:exec(function()
        t.assert_equals(1, 2)
    end)
end

Run test using luatest. The result will be:

[001] app-luatest/verbose_error_test.lua                              [ fail ]
[001] Test failed! Output from reject file /tmp/t/rejects/app-luatest/verbose_error.reject:
[001] Tarantool version is 3.2.0-entrypoint-35-g2cfba5eba
[001] TAP version 13
[001] 1..2
[001] # Started on Mon May 20 18:41:32 2024
[001] # Starting group: app-luatest.verbose_error
[001] not ok 1	app-luatest.verbose_error.test_usual_error
[001] #   ...ork/ee/tarantool/test/app-luatest/verbose_error_test.lua:17: expected: 2, actual: 1
[001] #   stack traceback:
[001] #   	...ork/ee/tarantool/test/app-luatest/verbose_error_test.lua:16: in function 'app-luatest.verbose_error.test_usual_error'
[001] #   	...
[001] #   	[C]: in function 'xpcall'
[001] #   artifacts:
[001] #   	master -> /tmp/t/001_app-luatest/artifacts/master-0Nw8NZCj7bCz
[001] not ok 2	app-luatest.verbose_error.test_verbose_error
[001] #   {"status":"fail","class":"LuatestError","message":"...ork/ee/tarantool/test/app-luatest/verbose_error_test.lua:26: expected: 2, actual: 1"} {"code":32,"type":"LuajitError","trace":[{"file":"./src/lua/utils.c","line":679}]}
[001] #   stack traceback:
[001] #   	...ork/ee/tarantool/test/app-luatest/verbose_error_test.lua:25: in function 'app-luatest.verbose_error.test_verbose_error'
[001] #   	...
[001] #   	[C]: in function 'xpcall'
[001] #   artifacts:
[001] #   	master -> /tmp/t/001_app-luatest/artifacts/master-0Nw8NZCj7bCz
[001] # Ran 2 tests in 0.345 seconds, 0 succeeded, 1 failed, 1 errored

The first test gives the expected message. The second gives additional information.

[ImeevMA]

Another reproducer in Tarantool 3.1+:

compat = require('compat')
compat.box_error_serialize_verbose = 'new'
compat.box_error_unpack_type_and_code = 'new'
t = require('luatest')
server = require('luatest.server')
s = server:new({alias = 'master'})
s:start()
s:exec(function() local t = require('luatest') t.assert_equals(1, 2) end)

The result

tarantool> s:exec(function() local t = require('luatest') t.assert_equals(1, 2) end)
---
- error:
    code: 32
    type: LuajitError
    message: '{"status":"fail","class":"LuatestError","message":"[string \"return
      s:exec(function() local t = require(''l...\"]:1: expected: 2, actual: 1"}'
    trace:
    - file: ./src/lua/utils.c
      line: 679
...

instead of

tarantool> s:exec(function() local t = require('luatest') t.assert_equals(1, 2) end)
---
- error: {'status': 'fail', 'class': 'LuatestError', 'message': '[string "return s:exec(function()
      local t = require(''l..."]:1: expected: 2, actual: 1'}
...