bug#51843: Ispell personal dictionary breaks other dictionaries

[Eli Zaretskii]

> From: Tor Kringeland <tor.a.s.kringeland@ntnu.no>
> Date: Sun, 14 Nov 2021 14:50:01 +0100
> 
> Using e.g. `ispell' with an English dictionary and setting
> `ispell-personal-dictionary' to, say, `/tmp/words.txt' will add new
> words to this file when using this dictionary.  However, if I change the
> dictionary to something else (like a Norwegian dictionary), I get the
> following output
> 
>   Starting new Ispell process /usr/local/bin/aspell with english 
> dictionary...done
>   ispell-init-process: Error: Expected language "nn" but got "en".
> 
> when running `ispell-word' on a misspelled word.  By extension this
> breaks `flyspell-mode'.  If I set `ispell-personal-dictionary' back to
> nil, though, things works as usual.
> 
> For reference this happens on a build of Emacs 29 from 11 November using
> `-Q' on macOS Catalina, though I remember having this problem for quite
> some time.

Isn't this the same problem with the LANG setting in the environment?