Adjust locale setting especially to fix Tofu in VT

* Prefer Eglish for system default
* Ensure ASCII in Linux VT console
* Prefer ISO 8601 date format with en_DK hack

home-manager/bash.nix

@@ -135,6 +135,7 @@
         source "${homemade-pkgs.posix_shared_functions}"
 
         if [ 'linux' = "$TERM" ]; then
+          export LANG=C # Avoid Tofu
           disable_blinking_cursor
         fi
       ''

home-manager/common.nix

@@ -79,6 +79,13 @@
       inherit edge-pkgs;
       inherit homemade-pkgs;
     };
+
+    # https://wiki.archlinux.jp/index.php/%E3%83%AD%E3%82%B1%E3%83%BC%E3%83%AB
+    # https://github.com/nix-community/home-manager/blob/fe56302339bb28e3471632379d733547caec8103/modules/home-environment.nix#L11
+    language = {
+      base = "ja_JP.UTF-8";
+      time = "en_DK.UTF-8"; # To prefer ISO 8601 format. See https://unix.stackexchange.com/questions/62316/why-is-there-no-euro-english-locale
+    };
   };
 
   # Let Home Manager install and manage itself.

home-manager/zsh.nix

@@ -292,6 +292,7 @@ in
       source_sh "${homemade-pkgs.posix_shared_functions}"
 
       if [ 'linux' = "$TERM" ]; then
+        export LANG=C # Avoid Tofu
         disable_blinking_cursor
       fi
 

nixos/configuration.nix

@@ -168,21 +168,10 @@
     };
   };
 
-  # TODO: Reconsider to set C or EN for servers
-  # Select internationalisation properties.
   i18n = {
-    defaultLocale = "ja_JP.UTF-8";
-
     extraLocaleSettings = {
-      LC_ADDRESS = "ja_JP.UTF-8";
-      LC_IDENTIFICATION = "ja_JP.UTF-8";
-      LC_MEASUREMENT = "ja_JP.UTF-8";
-      LC_MONETARY = "ja_JP.UTF-8";
-      LC_NAME = "ja_JP.UTF-8";
-      LC_NUMERIC = "ja_JP.UTF-8";
-      LC_PAPER = "ja_JP.UTF-8";
-      LC_TELEPHONE = "ja_JP.UTF-8";
-      LC_TIME = "ja_JP.UTF-8";
+      # https://wiki.archlinux.jp/index.php/%E3%83%AD%E3%82%B1%E3%83%BC%E3%83%AB
+      LC_TIME = "en_DK.UTF-8"; # To prefer ISO 8601 format. See https://unix.stackexchange.com/questions/62316/why-is-there-no-euro-english-locale
     };
   };
 }