I am sorry but it is completelly wrong

> +    if cfg.pid_file ~= default_cfg.pid_file then
> +        log.warn("then using with tarantoolctl option 'pid_file' is
> ignored") +        cfg.pid_file = default_cfg.pid_file
> +    end
How should this fix the issue?

> -            box.error(box.error.RELOAD_CFG, key);
> +            -- then started with tarantoolctl this option is set to
> +            -- default value, see #3214.
> +            if key == "pid_file" then
What is it "pid_file"?