On my home laptop running NixOS 19.03, in /etc/nixos/configuration.nix, I use the default locale settings:
i18n = {
consoleFont = "Lat2-Terminus16";
consoleKeyMap = "us";
defaultLocale = "en_US.UTF-8";
};
That's the only way I know to control locale settings in NixOS, and it's too broad. I want more granular control, so that I can use a mixture of US English and Colombian Spanish. (That's a consequence of my job, not a personal choice.) Specifically, I need these settings:
LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC=es_CO.UTF-8
LC_TIME=es_CO.UTF-8
LC_COLLATE="en_US.UTF-8"
LC_MONETARY=es_CO.UTF-8
LC_MESSAGES="en_US.UTF-8"
LC_PAPER=es_CO.UTF-8
LC_NAME=es_CO.UTF-8
LC_ADDRESS=es_CO.UTF-8
LC_TELEPHONE=es_CO.UTF-8
LC_MEASUREMENT=es_CO.UTF-8
LC_IDENTIFICATION=es_CO.UTF-8
LC_ALL=
On my work desktop (running Ubuntu 18.04), if I evaluate locale in bash, that's what I see. On my home NixOS system, each of those variables is either set to US English or nothing:
[jeff@jbb-dell:~/nix-jbb]$ locale
LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=
I thought maybe I should edit /etc/locale.conf, copying the settings from my work system into it. But when (on the NixOS system) I print that file to screen, it doesn't include any of the above variables except LANG:
[jeff@jbb-dell:~/nix-jbb]$ cat /etc/locale.conf
LANG=en_US.UTF-8
[jeff@jbb-dell:~/nix-jbb]$
Therefore the other variables, like LC_NUMERIC, must be getting set somewhere else. I'm worried that if I edit /etc/locale.conf I'll break my system. Is editing that file the right way to set granular locale information in NixOS? And if not, what is?
The option i18n.extralocalesettings is where to set those. E.g.:
i18n.extraLocaleSettings = {
LC_MESSAGES = "en_US.UTF-8";
LC_TIME = "de_DE.UTF-8";
}