let
  # Pinned nixpkgs, deterministic. Last updated: 2/12/21.
  #pkgs = import (fetchTarball("https://github.com/NixOS/nixpkgs/archive/a58a0b5098f0c2a389ee70eb69422a052982d990.tar.gz")) {};
  # Rolling updates, not deterministic.
  pkgs = import (fetchTarball "channel:nixpkgs-unstable") { };
  PKG_CONFIG_PATH = "${pkgs.openssl.dev}/lib/pkgconfig";
in pkgs.mkShell {
  buildInputs = with pkgs; [
    cargo
    rustc
    zsh
    bacon
    pkg-config
    openssl
];
  shellHook = "";
}