full_message

        # Exception.full_message

(from ruby core)
---
    exception.full_message(highlight: bool, order: [:top or :bottom]) ->  string

---

Returns formatted string of *exception*. The returned string is
formatted using the same format that Ruby uses when printing an uncaught
exceptions to stderr.

If *highlight* is `true` the default error handler will send the
messages to a tty.

*order* must be either of `:top` or `:bottom`, and places the error
message and the innermost backtrace come at the top or the bottom.

The default values of these options depend on `$stderr` and its `tty?`
at the timing of a call.