Use Determinate with nix-darwin

If you don’t yet have a nix-darwin configuration, we recommend creating one using one of Determinate Nix’s flake templates:

Generate a nix-darwin configuration using Nix


nix flake init --template "https://flakehub.com/f/DeterminateSystems/flake-templates/0#nix-darwin"

Follow the instructions in the welcome text to get started.

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:

flake.nix


{
  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 as 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.

If you’d like to set that custom configuration using nix-darwin, you can use the determinate nix-darwin module. Here’s an example nix-darwin configuration that writes custom settings:

flake.nix


{
  inputs.determinate.url = "https://flakehub.com/f/DeterminateSystems/determinate/3";
  inputs.nix-darwin = {
    url = "https://flakehub.com/f/nix-darwin/nix-darwin/0";
    inputs.nixpkgs.follows = "nixpkgs";
  };
  inputs.nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0";
 
  outputs = { determinate, nixpkgs, ... }: {
    darwinConfigurations."my-username-aarch64-darwin" = inputs.nix-darwin.lib.darwinSystem {
      inherit system;
      modules = [
        # Add the determinate nix-darwin module
        inputs.determinate.darwinModules.default
        ({ ... }: {
          # Let Determinate Nix handle Nix configuration rather than nix-darwin
          nix.enable = false;
 
          # Custom settings written to /etc/nix/nix.custom.conf
          determinate-nix.customSettings = {
            flake-registry = "/etc/nix/flake-registry.json";
          };
        })
      ];
    };
  };
}