NixOS warning for LC_ALL="C.UTF-8"

[JaredCorduan]

NixOS gives a warning when using LC_ALL="C.UTF-8". We use this here:

https://github.com/input-output-hk/cardano-ledger/blob/2eafa6e55723c4cd2ef04911674e8f66830661d5/shell.nix#L62

Using LC_ALL=en_US.utf-8 works on NixOS, but not everywhere else. It would be nice to have a solution that works everywhere.

See https://input-output-rnd.slack.com/archives/C03T9003RK5/p1660655829143089

[lehins]

This warning shows on OpenSUSE (probably others as well) when entering nix develop:

bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8): No such file or directory

[lehins]

I learned recently that this line is not needed for nix, hence is the warning.