{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    systems.url = "github:nix-systems/default";
  };

  outputs = { self, nixpkgs, systems, ... }:
    let eachSystem = nixpkgs.lib.genAttrs (import systems);
    in {
      packages = eachSystem (system:
        let pkgs = nixpkgs.legacyPackages.${system};
        in {
          soe = pkgs.callPackage ./package.nix {};
          default = self.packages.${system}.soe;
        });
    };
}