bug#40088: 27.0.90; Symbol’s value as variable is void: debugger-outer-match-data

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@gmail.com>
> Cc: michael_heerdegen@web.de,  joostkremers@fastmail.fm,
>   40088@debbugs.gnu.org,  monnier@iro.umontreal.ca
> Date: Sun, 22 Mar 2020 23:40:49 -0400
> 
> >> > It sounds like a very basic error.  How come we never saw it before?
> >> > Is it just luck?
> >> 
> >> Like I said, the debug.el code changed in Emacs 27 so that the bug can
> >> be triggered more often.
> >
> > Is this code used only in debug.el?
> 
> Actually, the call to backtrace--locals moved from debug.el to the new
> file backtrace.el (via backtrace-get-frames).  edebug.el and ert.el call
> backtrace-get-frames too.

So only backtrace-related functions can bump into this?  The root
cause sounded much more general to me.