# Pastebin mkwLmMKF
let
  pkgs =
    import (builtins.fetchTarball {
      # Latest commit hash : https://nixos.org/channels/nixpkgs-unstable/git-revision
      url = https://github.com/nixos/nixpkgs/archive/88d9f776091896cfe57dc6fbdf246e7d27d5f105.tar.gz;
      sha256 = "0z8a0g69fmbbzi77jhvhwafv73dn5fg3gsr0q828lss6j5qpx995";
    }) {};
  pkg =
    pkgs.haskellPackages.developPackage {
      root = pkgs.lib.cleanSource ./.;
    };
in
  with pkgs;
  if
    lib.inNixShell
  then
    pkg.overrideAttrs(attrs: {
      buildInputs = attrs.buildInputs ++ (with haskellPackages; [
        cabal-install
        ghcid
        lsof
        postgresql
      ]);
    })
  else pkg