NixOS Helix (master) use cache

[ChrHorn]

I'm using a Flake based setup to get Helix master. Until recently (1 or 2 weeks) fetching the cache kinda worked (about 80% success rate), but now I'm getting compilation at every new OS build. My Flake setup is pretty minimal, and I didn't change anything.

I saw there were some changes recently to the Flake, do I have to change anything? I'm not very well versed when it comes to Nix and have no idea how to debug these cache misses.

{
  nixConfig = {
    extra-substituters = [ "https://helix.cachix.org" ];
    extra-trusted-public-keys = [ "helix.cachix.org-1:ejp9KQpR1FBI2onstMQ34yogDm4OgU2ru6lIwPvuCVs=" ];
  };

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    helix.url = "github:helix-editor/helix";
  };

  outputs =
    {
      nixpkgs,
      helix,
      ...
    }@inputs:
    {
      nixosConfigurations.nixos-wsl =
        let
          system = "x86_64-linux";
        in
        nixpkgs.lib.nixosSystem {
          inherit system;
          modules = [
            {
              nixpkgs.overlays = [ helix.overlays.default ];
            }
            ./configuration.nix
          ];
        };
    };
}

[ChrHorn]

Removing

nixpkgs.overlays = [ helix.overlays.default ];

and then adding

inputs.helix.packages."${pkgs.system}".default

to packages has fixed the issue.