On Fri, Nov 17, 2017 at 1:08 PM Kaushal Modi <kaushal.modi@gmail.com> wrote:

> (gdb) xbacktrace
> Undefined command: "xbacktrace".  Try "help".
> (gdb)
>

Looks like that *is* the command.

Then is it possible it's related to
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=29332? Let me rebuild with
http://git.savannah.gnu.org/cgit/emacs.git/commit/?h=emacs-26&id=648c128b5f5eb8988aabcc2073b706d2561acd15
..
just in case.

-- 

Kaushal Modi