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

問題：

解決：

sudo locale-gen "en_US.UTF-8"
sudo dpkg-reconfigure locales
sudo vi /etc/default/locale 將裏面的內容改爲下面內容

LANG="en_US.UTF-8"
LC_ALL="en_US.UTF-8"