─[leonid@vasya-L460]─[~/work/mail/tarantool/tmp2]
└──╼ tarantool
Tarantool 2.5.2-11-g6bd5e23
type 'help' for interactive help
tarantool> box.cfg{listen="localhost:1918"}                                                                                                     
2020-12-04 14:30:15.666 [21046] main/103/interactive C> Tarantool 2.5.2-11-g6bd5e23
2020-12-04 14:30:15.666 [21046] main/103/interactive C> log level 5
2020-12-04 14:30:15.667 [21046] main/103/interactive I> mapping 268435456 bytes for memtx tuple arena...
2020-12-04 14:30:15.667 [21046] main/103/interactive I> mapping 134217728 bytes for vinyl tuple arena...
2020-12-04 14:30:15.672 [21046] main/103/interactive I> instance uuid 92ebfaef-4b56-40ce-95f0-3dd82380c1ba
2020-12-04 14:30:15.674 [21046] iproto/101/main I> binary: bound to 127.0.0.1:1918
2020-12-04 14:30:15.674 [21046] main/103/interactive I> initializing an empty data directory
2020-12-04 14:30:15.735 [21046] main/103/interactive I> assigned id 1 to replica 92ebfaef-4b56-40ce-95f0-3dd82380c1ba
2020-12-04 14:30:15.737 [21046] main/103/interactive I> cluster uuid af2956f6-1fff-4bc6-b35c-17c864ba31d2
2020-12-04 14:30:15.741 [21046] snapshot/101/main I> saving snapshot `./00000000000000000000.snap.inprogress'
2020-12-04 14:30:15.801 [21046] snapshot/101/main I> done
2020-12-04 14:30:15.803 [21046] main/103/interactive I> ready to accept requests
2020-12-04 14:30:15.805 [21046] main/103/interactive I> set 'log_level' configuration option to 5
2020-12-04 14:30:15.805 [21046] main/105/checkpoint_daemon I> scheduled next checkpoint for Fri Dec  4 16:22:34 2020
2020-12-04 14:30:15.806 [21046] main/103/interactive I> set 'listen' configuration option to "localhost:1918"
2020-12-04 14:30:15.807 [21046] main/103/interactive I> set 'log_format' configuration option to "plain"
---
...

tarantool> function test_error() box.error{code = 3 , reason = "Some reason"} end                                                               
---
...

tarantool> box.schema.user.grant('guest', 'super')                                                                                              
---
...

tarantool> 

tarantool> ┌─[leonid@vasya-L460]─[~/work/mail/tarantool]
└──╼ tarantool
Tarantool 2.5.2-11-g6bd5e23
type 'help' for interactive help
tarantool> nb = require('net.box')
---
...

tarantool> con = nb.connect("localhost:1918")                                                                                                   
---
...

tarantool> res, err = pcall(con.call, con, 'test_error')                                                                                        
---
...

tarantool> err:unpack()
---
- code: 3
  base_type: ClientError
  type: ClientError
  message: Some reason
  trace:
  - file: '[string "function test_error() box.error{code = 3 , re..."]'
    line: 1
...

tarantool>

-- Convert error object from pcall to lua, box or vshard error
-- object.
--
local function make_error(e)
    if type(e) == 'cdata' and ffi.istype('struct error', e) then
        -- box.error, return unpacked
        return box_error(e)
    elseif type(e) == 'string' then
        local ok, err = pcall(box.error, box.error.PROC_LUA, e)
        return box_error(err)
    elseif type(e) == 'table' then
        return setmetatable(e, {__tostring = json.encode})
    else
        return e
    end
end

tarantool.error.DatabaseError(7, "Can't modify data because this instance is in read-only mode")