Use Determinate with nix-darwin

You can use nix-darwin with Determinate without issue provided that you let Determinate Nix handle your Nix configuration rather than nix-darwin. To that end, you need to add this line to your nix-darwin configuration:

{
  darwinConfigurations.my-system-aarch64-darwin = nix-darwin.lib.darwinSystem {
    system = "aarch64-darwin";
    modules = [
      ({ ... }: {
        # Let Determinate Nix handle Nix configuration
        nix.enable = false;
      })
    ];
  };
}

To supply custom Nix configuration, such values for trusted-substituters and trusted-public-keys, you can use the /etc/nix/nix.custom.conf file. See our documentation on configuring Determinate Nix for more information.