I was getting errors such as man: can't set the locale; make sure $LC_* and $LANG are correct
when SSH’ing my Raspberry Pi box. Suggested fixes such as dpkg-reconfigure locales
didn’t help (I got a new error after selecting the correct locale – /usr/bin/locale: Cannot set LC_CTYPE to default locale: No such file or directory
).
This AskUbuntu thread has a good explanation of the problem and possible fixes. This StackOverflow thread has a good explanation of the Language variables themselves. It is common for macOS users coz the macOS /etc/ssh/ssh_config
file exports all the language variables and that confuses the remote machine. If you don’t want to fix it cleanly, a “rough” solution is to disable sending of language variables in the Terminal app or iTerm. Special shoutout to this answer from the aforementioned AskUbuntu thread that explains the problem well and gives a good fix.