{
  inputs = {
    nixpkgs.url = "flake:nixpkgs/nixpkgs-unstable";
    utils.url = "flake:flake-utils";
  };

  outputs = { self, nixpkgs, utils, ... }: utils.lib.eachSystem [
    "aarch64-darwin"
    "x86_64-darwin"
    "aarch64-linux"
    "x86_64-linux"
  ]
    (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        # enable musl on Linux makes the build time 100x slower
        # since it will trigger a toolchain rebuild
        # if nixpkgs.legacyPackages.${system}.stdenv.hostPlatform.isLinux
        # then nixpkgs.legacyPackages.${system}.pkgsMusl
        # else nixpkgs.legacyPackages.${system};

        crunchy-cli = pkgs.rustPlatform.buildRustPackage.override { stdenv = pkgs.clangStdenv; } rec {
          pname = "crunchy-cli";
          inherit ((pkgs.lib.importTOML ./Cargo.toml).package) version;

          src = pkgs.lib.cleanSource ./.;

          cargoLock = {
            lockFile = ./Cargo.lock;
            allowBuiltinFetchGit = true;
          };

          buildNoDefaultFeatures = true;
          buildFeatures = [ "openssl" ];

          nativeBuildInputs = [
            pkgs.pkg-config
          ] ++ pkgs.lib.optionals pkgs.stdenv.isDarwin [
            pkgs.xcbuild
          ];

          buildInputs = [
            pkgs.openssl
          ] ++ pkgs.lib.optionals pkgs.stdenv.isDarwin [
            pkgs.darwin.Security
          ];
        };
      in
      {
        packages.default = crunchy-cli;

        overlays.default = _: prev: {
          crunchy-cli = prev.crunchy-cli.override { };
        };

        devShells.default = pkgs.mkShell {
          packages = with pkgs; [
            cargo
            clippy
            rust-analyzer
            rustc
            rustfmt
          ];

          inputsFrom = builtins.attrValues self.packages.${system};

          buildInputs = [
            pkgs.openssl
            pkgs.libiconv
          ] ++ pkgs.lib.optionals pkgs.stdenv.isDarwin [
            pkgs.darwin.apple_sdk.frameworks.CoreServices
            pkgs.darwin.Security
          ];

          RUST_SRC_PATH = pkgs.rustPlatform.rustLibSrc;
        };

        formatter = pkgs.nixpkgs-fmt;
      }
    );
}