After using the testing repo for Debian Buster to install Emacs 27 I ran into an issue where spellcheck through ispell would not work
debian-ispell-set-startup-menu: Symbol's value as variable is void: ispell-menu-map-needed
Turns out the issue was in
dictionaries-common, and fixed ages ago. Debian doesn’t like to keep with the times though, so I had to also install
dictionaries-common from the testing repo to finally fix the issue!
sudo apt --target-release=testing install dictionaries-common
Starting new Ispell process ispell with default dictionary...done Checking spelling of THIS... THIS is correct