Sorry for the late reply. I will create a Debian VM and see if I can replicate it with the latest Emacs version built from source and get back to you. I did notice in a internet search that there's another bug referencing this one https://mail.gnu.org/archive/html/bug-gnu-emacs/2020-09/msg00169.html

On Sun, Apr 24, 2022 at 9:20 AM Lars Ingebrigtsen <larsi@gnus.org> wrote:

Will Bush <will.g.bush@gmail.com> writes:

> git clone https://github.com/adobe-fonts/adobe-blank.git
> cd adobe-blank
> sudo cp AdobeBlank.ttf /usr/share/fonts/
> fc-cache
> time emacs -Q --eval '(message "︵")' -kill
>
> And it took 4 minutes in the virtual machine!

I tried this on Debian/bookworm with Emacs 28.1 (and 29), but was unable
to see anything odd -- but Emacs chose to use the Noto font for that
character here.

Are you still seeing this problem in recent Emacs/OS versions?

--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog: http://lars.ingebrigtsen.no