{
  compiler ? "ghc884"
}:

let
  pkgs = import (
    builtins.fetchGit {
      name = "nixpkgs-pinned";
      url = https://github.com/NixOS/nixpkgs/;
      ref = "refs/heads/release-20.09";
      rev = "e065200fc90175a8f6e50e76ef10a48786126e1c";
    }) {
      # Pass no config for purity
          config = {};
              overlays = [];
    };
  hp = pkgs.haskell.packages."${compiler}";
  src = pkgs.nix-gitignore.gitignoreSource [] ./.;
  drv = hp.callCabal2nix "Hash2Pub" "${src}/Hash2Pub.cabal" {};
in
{
  my_project = drv;
  shell = hp.shellFor {
    withHoogle = true;
    packages = p: [ drv ];
    buildInputs = with hp;
      [
        haddock
        cabal-install
        hlint
        stylish-haskell
        pkgs.python3Packages.asn1ate
      ];
  };
}