On Funtoo, there are two configuration files responsible for your language settings: /etc/locale.gen and /etc/env.d/00basic. First file has only en_US.UTF-8 locale enabled. Last one is a default shipped file comes from stage3 and responsible for en_US.UTF-8 locale system-wide. Not recommended to edit.
The following steps will guide you through the process of setting up the default system language, using French Canadian as an example.
First you will need to edit /etc/locale.gen:
root#nano -w /etc/locale.gen
Specify your preferred locale with the accompanying character format (you will mostly want UTF-8):
Note
It is recommended to keep the preconfigured en_US.UTF-8 locale as a fallback.
/etc/locale.gen
en_US.UTF-8 UTF-8
fr_CA.UTF-8 UTF-8
To determine an appropriate locale for your system, you should take a look into /usr/share/i18n/SUPPORTED for the default list of supported combinations or check the /usr/share/i18n/locales/ directory for a list of valid values.
Warning
You are strongly advised to use at least one UTF-8 locale since some applications may require it.