System for configuration is local system not the target system

[i1i1]

I'm finding it weird that local system is used for nixpkgs here:

nixos-rk3588/demo/flake.nix

Lines 13 to 36 in 349f39d

	# using the same nixpkgs as nixos-rk3588 to utilize the cross-compilation cache.
	inherit (nixos-rk3588.inputs) nixpkgs;
	boardModule = nixos-rk3588.nixosModules.orangepi5;
	# 1. for cross-compilation on x86_64-linux
	system = "x86_64-linux";
	# Compile the kernel using a cross-compilation tool chain
	# Which is faster than emulating the target system.
	pkgsKernel = import nixpkgs {
	localSystem = "x86_64-linux";
	crossSystem = "aarch64-linux";
	};
	# 2. for native compilation on aarch64-linux SBCs.
	# system = "aarch64-linux";
	# native compilation tool chain for the linux kernel
	# pkgsKernel = nixpkgs;
	in {
	colmena = {
	meta = {
	nixpkgs = import nixpkgs {inherit system;};
	rk3588 = {
	inherit nixpkgs pkgsKernel;
	};
	};

Can you explain how it works, because if you remove colmena from the configuration and make it regular nixos configuration and try to crosscompile it would look like this:

nixpkgs.lib.nixosSystem {
  system = "x86_64-linux";
  modules = [
    nixos-rk3588.nixosModules.orangepi5.core
    nixos-rk3588.nixosModules.orangepi5.sd-image
    ./configuration.nix
  ];

  specialArgs.rk3588 = {
    inherit nixpkgs;
    pkgsKernel = import nixpkgs {
      localSystem = "x86_64-linux";
      crossSystem = "aarch64-linux";
    };
  };
}

Which is a bit weird, cause system is still aarch64-linux.

[i1i1]

Nevermind. It doesn't work as I described.

I've set nixosSystem as follows:

nixpkgs.lib.nixosSystem {
  system = "aarch64-linux";
  modules = [
    nixos-rk3588.nixosModules.orangepi5.core
    nixos-rk3588.nixosModules.orangepi5.sd-image
    ./configuration.nix
  ];

  specialArgs.rk3588 = {
    inherit nixpkgs;
    pkgsKernel = import nixpkgs {
      localSystem = "x86_64-linux";
      crossSystem = "aarch64-linux";
    };
  };
}

and used my orangepi 5 as remote builder (as described here) and everything worked flawlessly. Maybe example should be updated or I can add example featuring regular deployment.