{ nixpkgs ? import <nixpkgs> {}, compiler ? "default", doBenchmark ? false }:

let

  inherit (nixpkgs) pkgs;

  f = { mkDerivation, aeson, base, opaleye, postgresql-simple
      , product-profunctors, servant, servant-server, stdenv, text, time
      , warp
      }:
      mkDerivation {
        pname = "mateamt";
        version = "0.0.0.0";
        src = ./.;
        isLibrary = false;
        isExecutable = true;
        executableHaskellDepends = [
          aeson base opaleye postgresql-simple product-profunctors servant
          servant-server text time warp
        ];
        description = "A whole new matemat";
        license = stdenv.lib.licenses.agpl3;
      };

  haskellPackages = if compiler == "default"
                       then pkgs.haskellPackages
                       else pkgs.haskell.packages.${compiler};

  variant = if doBenchmark then pkgs.haskell.lib.doBenchmark else pkgs.lib.id;

  drv = variant (haskellPackages.callPackage f {});

in

  if pkgs.lib.inNixShell then drv.env else drv