{ pkgs ? import <nixpkgs> {} }:

pkgs.stdenv.mkDerivation rec {
  name = "dhall-simple";
  version = "1.20.1";

  src = pkgs.fetchurl {
    url = "https://github.com/dhall-lang/dhall-haskell/releases/download/${version}/dhall-${version}-x86_64-linux.tar.bz2";
    sha256 = "1ycb0pglwi9k1pn4qqjyvd4bi54000fb9aqxnn550a515rm6cb03";
  };

  installPhase = ''
    mkdir -p $out/bin
    DHALL=$out/bin/dhall
    install -D -m555 -T dhall $DHALL

    mkdir -p $out/etc/bash_completion.d/
    $DHALL --bash-completion-script $DHALL > $out/etc/bash_completion.d/dhall-completion.bash
  '';
}