rebuild not working

modules/system/nix/nixpkgs.nix

@@ -0,0 +1,45 @@
+{
+  # Global nixpkgs configuration. This is ignored if nixpkgs.pkgs is set
+  # which is a case that should be avoided. Everything that is set to configure
+  # nixpkgs must go here.
+  nixpkgs = {
+    # Configuration reference:
+    # <https://nixos.org/manual/nixpkgs/unstable/#chap-packageconfig>
+    #  config = {
+    #    # Allow broken packages to be built. Setting this to false means packages
+    #    # will refuse to evaluate sometimes, but only if they have been marked as
+    #    # broken for a specific reason. At that point we can either try to solve
+    #    # the breakage, or get rid of the package entirely.
+    #    allowBroken = false;
+    #    allowUnsupportedSystem = true;
+    #
+    #    # Really a pain in the ass to deal with when disabled. True means
+    #    # we are able to build unfree packages without explicitly allowing
+    #    # each unfree package.
+    #    allowUnfree = true;
+    #
+    #    # Default to none, add more as necessary. This is usually where
+    #    # electron packages go when they reach EOL.
+    #    permittedInsecurePackages = [];
+    #
+    #    # Nixpkgs sets internal package aliases to ease migration from other
+    #    # distributions easier, or for convenience's sake. Even though the manual
+    #    # and the description for this option recommends this to be true, I prefer
+    #    # explicit naming conventions, i.e., no aliases.
+    #    allowAliases = true;
+    #
+    #    # Enable parallel building by default. This, in theory, should speed up building
+    #    # derivations, especially rust ones. However setting this to true causes a mass rebuild
+    #    # of the *entire* system closure, so it must be handled with proper care.
+    #    enableParallelBuildingByDefault = false;
+    #
+    #    # List of derivation warnings to display while rebuilding.
+    #    #  See: <https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/check-meta.nix>
+    #    # NOTE: "maintainerless" can be added to emit warnings
+    #    # about packages without maintainers but it seems to me
+    #    # like there are more packages without maintainers than
+    #    # with maintainers, so it's disabled for the time being.
+    #    showDerivationWarnings = [];
+    #  };
+  };
+}