nixos/i18n: don't build all supportedLocales by default

nixos/doc/manual/from_md/release-notes/rl-2211.section.xml

@@ -93,6 +93,16 @@
           compatible</emphasis>.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          <literal>i18n.supportedLocales</literal> is now by default
+          only generated with the default locale set in
+          <literal>i18n.defaultLocale</literal>. This got copied over
+          from the minimal profile and reduces the final system size by
+          200MB. If you require all locales installed set the option to
+          <literal>[ &quot;all&quot; ]</literal>.
+        </para>
+      </listitem>
       <listitem>
         <para>
           The <literal>isPowerPC</literal> predicate, found on

nixos/doc/manual/release-notes/rl-2211.section.md

@@ -43,6 +43,10 @@ In addition to numerous new and upgraded packages, this release has the followin
   `lib.systems.parse.isCompatible` still exists, but has changed semantically:
   Architectures with differing endianness modes are *no longer considered compatible*.
 
+- `i18n.supportedLocales` is now by default only generated with the default locale set in `i18n.defaultLocale`.
+  This got copied over from the minimal profile and reduces the final system size by 200MB.
+  If you require all locales installed set the option to ``[ "all" ]``.
+
 - The `isPowerPC` predicate, found on `platform` attrsets (`hostPlatform`, `buildPlatform`, `targetPlatform`, etc) has been removed in order to reduce confusion.  The predicate was was defined such that it matches only the 32-bit big-endian members of the POWER/PowerPC family, despite having a name which would imply a broader set of systems.  If you were using this predicate, you can replace `foo.isPowerPC` with `(with foo; isPower && is32bit && isBigEndian)`.
 
 - PHP 7.4 is no longer supported due to upstream not supporting this

nixos/modules/config/i18n.nix

@@ -53,7 +53,8 @@ with lib;
 
       supportedLocales = mkOption {
         type = types.listOf types.str;
-        default = ["all"];
+        default = [ (config.i18n.defaultLocale + "/UTF-8") ];
+        defaultText = literalExpression "[ (config.i18n.defaultLocale + \"/UTF-8\") ]";
         example = ["en_US.UTF-8/UTF-8" "nl_NL.UTF-8/UTF-8" "nl_NL/ISO-8859-1"];
         description = ''
           List of locales that the system should support.  The value

nixos/modules/profiles/minimal.nix

@@ -8,9 +8,6 @@ with lib;
 {
   environment.noXlibs = mkDefault true;
 
-  # This isn't perfect, but let's expect the user specifies an UTF-8 defaultLocale
-  i18n.supportedLocales = [ (config.i18n.defaultLocale + "/UTF-8") ];
-
   documentation.enable = mkDefault false;
 
   documentation.nixos.enable = mkDefault false;