Replace GNU coreutils with uutils.

nix/configuration/roles/uutils/default.nix

@@ -0,0 +1,33 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  imports = [ ];
+
+  options.me = {
+    uutils.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = "Whether we want to replace GNU coreutils with uutils (a rust drop-in replacement).";
+    };
+  };
+
+  config = lib.mkIf config.me.uutils.enable (
+    lib.mkMerge [
+      {
+        # environment.corePackages automatically installes coreutils-full, so merely installing uutils-coreutils-noprefix is insufficient for replacing GNU coreutils.
+        nixpkgs.overlays = [
+          (final: prev: {
+            coreutils = final.uutils-coreutils-noprefix;
+            coreutils-full = final.uutils-coreutils-noprefix;
+          })
+        ];
+      }
+    ]
+  );
+}