{
  inputs = {
    flake-utils.url = "github:numtide/flake-utils";
    mozilla = {
      url = "github:mozilla/nixpkgs-mozilla";
      flake = false;
    };
    naersk.url = "github:nmattia/naersk";
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
  };
  outputs = { self, flake-utils, mozilla, naersk, nixpkgs }: flake-utils.lib.eachDefaultSystem (
    system:
      let
        overlay = final: prev:
          let
            # rustChannel = final.rustChannelOf {
            #   channel = "stable";
            #   date = "2021-09-09";
            #   sha256 = "sha256-HNIlEerJvk6sBfd8zugzwSgSiHcQH8ZbqWQn9BGfmpo=";
            # };
            rustChannel = final.rustChannelOf {
              channel = "nightly";
              date = "2021-10-25";
              sha256 = "sha256-/zS2GztCeH6kc3ZjhBRvT7Pbnea5JvGBuWdZmagh788=";
            };
            rust = rustChannel.rust.override {
              extensions = [ "rust-src" ];
            };
          in
            {
              rustc = rust;
              cargo = rust;
            };
        pkgs = import nixpkgs {
          inherit system;
          overlays = [
            (import "${mozilla}/rust-overlay.nix")
            overlay
          ];
        };
        naerskLib = pkgs.callPackage "${naersk}/default.nix" {};
        persea = naerskLib.buildPackage {
          pname = "persea";
          src = ./.;
        };
      in
        {
          defaultPackage = persea;
          devShell = pkgs.mkShell {
            buildInputs = with pkgs; [
              cargo
              cargo-edit
              rust-analyzer
              rustfmt

              pkg-config
              openssl
            ];
          };
        }
  );
}