bug#36613: gdb: error on M-x menu-bar-open

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Sat, 13 Jul 2019 06:45:17 +0200
> Cc: 36613@debbugs.gnu.org
> 
> > On tty/Ubuntu Terminal:
> >
> > ~$ emacs -Q
> > M-x gdb
> > Run gdb (like this): gdb -i=mi
> > M-x toggle-debug-on-error
> > M-x menu-bar-open
> >
> > Debugger entered--Lisp error: (wrong-type-argument listp gud-print)
> >   popup-menu(gud-print (#<window 1 on *gud*> 2 (1 . 0) 0 nil 2 (1 . 0)
> > nil (0 . 0) (1 . 0)) nil t)
> >   menu-bar-open()
> >   funcall-interactively(menu-bar-open)
> 
> I'm unable to reproduce this bug in Emacs 27

Did you do this on a TTY frame?  The OP specifically says "on tty".