raw-efi hanging on boot with UTM and apple virtualisation

[jamesla]

I'm using the raw-efi nixos-generator to build an image that can run under UTM using apples virtualization engine however it hangs on boot.

I've cut the example right back to a simple example - that means no configuration.nix and no hardware-configuration.nix - which if I understand correctly it shouldn't need to in order to boot a simple example.

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.05";

    nixos-generators = {
      url = "github:nix-community/nixos-generators";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };
  outputs = { self, nixpkgs, nixos-generators, ... }: let
    system = "aarch64-linux";
  in {
    packages.aarch64-darwin = {
      default = nixos-generators.nixosGenerate {
        inherit system;
        format = "raw-efi";
      };
    };
  };
}

It builds fine but when I boot the image using UTM (with apples virtualisation engine) it hangs at the UEFI screen (full hang keys locked and can't type etc).

FYI the error it shows regarding `EFI_RNG_PROTOCOL is actually just a warning and I get that with the manually installed version however with that it proceeds and boots.

FYI2 If I boot from the nixos iso and install using the manual install commands it works fine so I know that nixos is compatible with UTM/Apple virtualisation.

FYI3 If I load this same image using UTM with QEMU virtualisation it boots fine.