FR: nixpkgs.flake.{source,setNixPath,setFlakeRegistry} settings

[n8henrie]

These three settings seem like handy newish additions (24.05) for which it might make sense to have nix-darwin equivalents

• nixpkgs.flake.source
• nixpkgs.flake.setNixPath
• nixpkgs.flake.setFlakeRegistry

With a flake-based NixOS system, these are all set by default and result in registry settings in /etc/nix/registry.json; in contrast mine is empty by default on nix-darwin.

The implementation looks fairly trivial: https://github.com/NixOS/nixpkgs/blob/nixos-unstable/nixos/modules/misc/nixpkgs-flake.nix, I think a workaround is as simple as:

nix = lib.optionalAttrs pkgs.stdenv.isDarwin {
    nixPath = [ "nixpkgs=flake:nixpkgs" ];
    registry.nixpkgs.to = {
      type = "path";
      path = config.nixpkgs.source;
    } // {
# remainder of platform-independent nix config
}

[DaGenix]

@n8henrie - I think this was maybe done in 8714f9e ?

[n8henrie]

Indeed! Thanks for the heads up!

$ nix eval .#darwinConfigurations.mymachine.config.nixpkgs.flake.source
"/nix/store/kjny8s47s35v10a4rcdyrir2dklbj0v9-source"
$ nix eval .#darwinConfigurations.mymachine.config.nixpkgs.flake.setFlakeRegistry
true
$ nix eval .#darwinConfigurations.mymachine.config.nixpkgs.flake.setNixPath
true