manpath: can't set the locale; make sure $LC_* and $LANG are correct

Try this https://gist.github.com/SimonSun1988/2ef7db45e46b889783647d941ec15e4d

sudo locale-gen "en_US.UTF-8"
sudo dpkg-reconfigure locales

and in file /etc/default/locale add line LC_ALL="en_US.UTF-8" and relogin to your server.

For CentOS this worked for me.

Add these lines to /etc/environment

LANG=en_US.utf-8
LC_ALL=en_US.utf-8

Edit your /etc/locale.gen then uncomment the following line:

en_GB.UTF-8 UTF-8

Run:

sudo locale-gen en_GB.UTF-8 UTF-8
sudo update-locale en_GB.UTF-8 UTF-8
export LANGUAGE=en_GB.UTF-8
export LC_ALL=en_GB.UTF-8

Verify it;

locale

You may get:

LANG=en_GB.UTF-8
LANGUAGE=en_GB.UTF-8
LC_CTYPE="en_GB.UTF-8"
LC_NUMERIC="en_GB.UTF-8"
LC_TIME="en_GB.UTF-8"
LC_COLLATE="en_GB.UTF-8"
LC_MONETARY="en_GB.UTF-8"
LC_MESSAGES="en_GB.UTF-8"
LC_PAPER="en_GB.UTF-8"
LC_NAME="en_GB.UTF-8"
LC_ADDRESS="en_GB.UTF-8"
LC_TELEPHONE="en_GB.UTF-8"
LC_MEASUREMENT="en_GB.UTF-8"
LC_IDENTIFICATION="en_GB.UTF-8"
LC_ALL=en_GB.UTF-8

And Done !!!