On a freshly installed CentOS 7 machine, I got the following notice when I SSH’d into the server.
warning: setlocale: LC_CTYPE: cannot change locale (UTF-8): No such file or directory
The fix is pretty straight-forward. On the server (not your client), edit the file /etc/environment and add the following lines.
(You’ll need root privileges to do this)
$ cat /etc/environment LANG=en_US.utf-8 LC_ALL=en_US.utf-8
Log out & back in and you should notice the warning message is gone.