How to use --flake

[Mic92]

it seems that nixosConfigurations.<machine> is not overridable, hence the question is how to use --flake.

[Sorixelle]

Looks like it depends on NixOS/nixpkgs#101475. A workaround for now would be doing something like:

{
  nixosConfigurations = let
    lib = nixpkgs.lib;
  in {
    machineName = (lib.makeOverridable lib.nixosSystem) {
      # ...
    };
  };
}

[legendofmiracles]

How do you even get so far? Whenever I try to use the --flake option it tells me that the option is not found:

> nixos-generate --system aarch-64 --flake ./dotnix#nixosConfigurations.pi
error: 'flake' is not a recognised command
Try 'nix --help' for more information.

Weirdly enough the error itself seems to be coming from nix. Not nixos-generate...

[Sorixelle]

You need to make sure nixos-generate is using a flake-enabled Nix (ie. nixos-generate.override { nix = nixUnstable; }).

[Pacman99]

Can the --flake feature be implemented with NixOS/nixpkgs#143207 instead? It seems like that could be a better solution and not require users to set mkOverridable