== default.nix ==

{ mkDerivation, base, beam-core, beam-migrate, beam-sqlite
, sqlite-simple, stdenv, text
}:
mkDerivation {
  pname = "beam";
  version = "0.1.0.0";
  src = ./.;
  isLibrary = false;
  isExecutable = true;
  executableHaskellDepends = [
    base beam-core beam-migrate beam-sqlite sqlite-simple text
  ];
  license = "unknown";
  hydraPlatforms = stdenv.lib.platforms.none;
}

== release.nix ==

let
  pkgs = import <nixpkgs> { };
in
  pkgs.haskellPackages.callPackage ./default.nix { }

== shell.nix ==

{ nixpkgs ? import <nixpkgs> {} }:
let
  inherit (nixpkgs) pkgs;
  inherit (pkgs) haskellPackages;

  project = import ./release.nix;
in
  pkgs.stdenv.mkDerivation {
    name = "shell";
    buildInputs = project.env.nativeBuildInputs ++ [
      haskellPackages.cabal-install
      haskellPackages.yesod-bin
      pkgs.cabal2nix
      pkgs.nix
      pkgs.postgresql
      (import ~/.config/nixpkgs/vim.nix)
    ];
  }

========

build with `nix-build release.nix`
shell with `nix-shell`