getting error: attribute 'complete' missing for flakes

[firstdorsal]

Hi! Any idea why this is happening with my setup?

error:
       … while calling the 'head' builtin

         at /nix/store/bwibdavbf6p8lci025h3qmln6laq5x82-source/lib/attrsets.nix:922:11:

          921|         || pred here (elemAt values 1) (head values) then
          922|           head values
             |           ^
          923|         else

       … while evaluating the attribute 'value'

         at /nix/store/bwibdavbf6p8lci025h3qmln6laq5x82-source/lib/modules.nix:807:9:

          806|     in warnDeprecation opt //
          807|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          808|         inherit (res.defsFinal') highestPrio;

       (stack trace truncated; use '--show-trace' to show the full trace)

       error: attribute 'complete' missing

       at /nix/store/x8a3awk0q2r5wab1307pb3g96p7xqmr3-source/configuration.nix:267:8:

          266|
          267|       (fenix.complete.withComponents [
             |        ^
          268|         "cargo"

In flake.nix

{
  description = "Pauls Config";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
    nixpkgs-unstable.url = "github:nixos/nixpkgs/nixos-unstable";

    fenix = {
      url = "github:nix-community/fenix";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    home-manager = {
      url = "github:nix-community/home-manager/release-23.11";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    plasma-manager = {
      url = "github:pjones/plasma-manager";

      inputs = {
        nixpkgs.follows = "nixpkgs";
        home-manager.follows = "home-manager";
      };
    };
  };

  outputs = inputs @ {
    self,
    nixpkgs,
    nixpkgs-unstable,
    home-manager,
    plasma-manager,
    fenix,
    ...
  }: let
    system = "x86_64-linux";
    username = "paul";
    hostname = "nixos";
    stateVersion = "23.11";
    shellAliases = {
      code = "codium";
      ll = "ls -alh";
      ez = "eza -la";
    };
    defaultApplicationHandlers = {
      "inode/directory".value = "org.kde.dolphin.desktop;";
      "x-scheme-handler/geo".value = "qwant-maps-geo-handler.desktop;";
      "x-scheme-handler/http".value = "brave-browser.desktop;";
      "x-scheme-handler/https".value = "brave-browser.desktop;";
      "x-scheme-handler/mailto".value = "thunderbird.desktop;";
      "x-scheme-handler/sgnl".value = "signal-desktop.desktop";
      "x-scheme-handler/signalcaptcha".value = "signal-desktop.desktop";
      "text/*".value = "codium.desktop";
      "text/plain".value = "codium.desktop";
      "application/x-zerosize".value = "codium.desktop";
    };
    unstable = import nixpkgs-unstable {inherit system;};
  in {
    formatter.x86_64-linux = nixpkgs.legacyPackages.x86_64-linux.alejandra;
    packages.x86_64-linux.default = fenix.packages.x86_64-linux.minimal.toolchain;

    nixosConfigurations.${hostname} = nixpkgs.lib.nixosSystem {
      inherit system;
      specialArgs = {
        inherit unstable;
        inherit fenix;
      };
      modules = [
        ./configuration.nix

        home-manager.nixosModules.home-manager
...

In configuration.nix

{
  config,
  pkgs,
  lib,
  unstable,
  fenix,
  ...
}: let
  stateVersion = "23.11";
in {
  imports = [./hardware-configuration.nix];

  nix.settings.experimental-features = ["nix-command" "flakes"];

  nixpkgs.overlays = [(final: prev: {sudo = prev.sudo.override {withInsults = true;};}) fenix.overlays.default];

...

environment = {
    sessionVariables = {
      STEAM_FORCE_DESKTOPUI_SCALING = "2";
    };
    systemPackages = with pkgs; [
      firefox
      thunderbird
      tor-browser
      brave
      spotify
      keepassxc
      signal-desktop

      (fenix.complete.withComponents [
        "cargo"
        "clippy"
        "rust-src"
        "rustc"
        "rustfmt"
      ])
      rust-analyzer-nightly

[firstdorsal]

Fixed it. It works by prefixing fenix.complete.withComponents with pkgs:

    systemPackages = with pkgs; [
      firefox
      thunderbird
      tor-browser
      brave
      spotify
      keepassxc
      signal-desktop

      (pkgs.fenix.complete.withComponents [
        "cargo"
        "clippy"
        "rust-src"
        "rustc"
        "rustfmt"
      ])
      rust-analyzer-nightly