hermetic error

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    home-manager.url = "github:nix-community/home-manager";
    home-manager.inputs.nixpkgs.follows = "nixpkgs";
    sops-nix.url = "github:Mic92/sops-nix";
    vscode-server.url = "github:nix-community/nixos-vscode-server";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { nixpkgs, home-manager, sops-nix, vscode-server, flake-utils, ... }: 
  flake-utils.lib.eachDefaultSystem (system: 

  let
   pkgs = import nixpkgs { inherit system; }; 
  in
  {
    colmena = {
      meta.nixpkgs = pkgs;

      defaults  = { pkgs, ... }:{
        imports = [
          ./modules/default.nix
          sops-nix.nixosModules.sops
          vscode-server.nixosModules.default
          home-manager.nixosModules.home-manager
          {
            home-manager.useGlobalPkgs = true;
            home-manager.useUserPackages = true;
            home-manager.users.root = import ./users/root/home.nix;
          }
        ];
      };

      # Servers
      nhqih-misc  = import ./servers/nhq/nhqih-misc/configuration.nix;
# 
      # nhqps-amp
      nhqiv-hass  = import ./servers/nhq/nhqiv-hass/configuration.nix;
      nhqiv-jump  = import ./servers/nhq/nhqiv-jump/configuration.nix;
      nhqiv-stats = import ./servers/nhq/nhqiv-stats/configuration.nix;
      nhqiv-nginx = import ./servers/nhq/nhqiv-nginx/configuration.nix;
      nhqiv-forge = import ./servers/nhq/nhqiv-forge/configuration.nix;
      nhqiv-peck  = import ./servers/nhq/nhqiv-peck/configuration.nix;
      nhqiv-prun1 = import ./servers/nhq/nhqiv-prun1/configuration.nix;

      nhqpv-nginx = import ./servers/nhq/nhqpv-nginx/configuration.nix;

      # nhqps-svr2
      nhqiv-ldap  = import ./servers/nhq/nhqiv-ldap/configuration.nix;
      nhqiv-paper = import ./servers/nhq/nhqiv-paper/configuration.nix;
      nhqiv-prun2 = import ./servers/nhq/nhqiv-prun2/configuration.nix;
      nhqpv-jelly = import ./servers/nhq/nhqpv-jelly/configuration.nix;
      nhqpv-sso   = import ./servers/nhq/nhqpv-sso/configuration.nix;

      # ngcpv-e2
      #ngcpv-cerberus = import ./servers/ngc/ngcpv-cerberus/configuration.nix;

      # Devices 
      korra = {
        imports = [ 
          ./devices/korra/configuration.nix 
          home-manager.nixosModules.home-manager
            {
              home-manager.useGlobalPkgs = true;
              home-manager.useUserPackages = true;
              home-manager.users.andrea = import ./users/andrea/home.nix;
            }
        ];
      };

      manjiro = {
        imports = [ 
          ./devices/manjiro/configuration.nix 
          home-manager.nixosModules.home-manager
            {
              home-manager.useGlobalPkgs = true;
              home-manager.useUserPackages = true;
              home-manager.users.andrea = import ./users/andrea/home.nix;
            }
        ];
      };
    };
  });
}

error:

error:
       … while calling the 'attrNames' builtin

         at «string»:1:190:

            1| with builtins; let assets = getFlake "path:/tmp/colmena-assets-V2fSxQ?lastModified=1723061186&narHash=sha256-AAS0sU1mOejiRrJUbk/8Ou6HwGp8VD32efExlVf7zbI%3D"; hive = assets.processFlake; in attrNames hive.nodes
             |                                                                                                                                                                                              ^

       … while evaluating the attribute 'nodes'

         at /nix/store/2x4j8wm0d400n45sg1nxwnk4l5d7n3vb-source/eval.nix:186:3:

          185|
          186|   nodes = listToAttrs (map (name: { inherit name; value = evalNode name (configsFor name); }) nodeNames);
             |   ^
          187|   toplevel =         lib.mapAttrs (_: v: v.config.system.build.toplevel) nodes;

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

       error: meta.nixpkgs must be specified in hermetic mode.
[ERROR] -----
[ERROR] Operation failed with error: Child process exited with error code: 1
Hint: Backtrace available - Use `RUST_BACKTRACE=1` environment variable to display a backtrace
andrea@korra ~/c/nixfiles2 (main) [1]>