Subject: bug#67477: Automake warns that $(?D) is a non-POSIX variable name

From: Quinn Grier <[email-masked]>
Date: Mon, 27 Nov 2023 14:42:05 -0800

Naturally, now that I've reported this bug after I couldn't find it
being already reported, I search again and find that it was already
reported a long time ago:
<https://debbugs.gnu.org/cgi/bugreport.cgi?bug=9587>.