Merge pull request #126137 from lrworth/nix-direnv-configurable-flakes

{ lib, stdenv, fetchFromGitHub, gnugrep, nixUnstable }:

{ lib

, stdenv

, fetchFromGitHub

, gnugrep

, nixStable

, nixUnstable

, enableFlakes ? false

}:

let

  nix = if enableFlakes then nixUnstable else nixStable;

in

stdenv.mkDerivation rec {

  pname = "nix-direnv";

  version = "1.2.6";

  # Substitute instead of wrapping because the resulting file is

  # getting sourced, not executed:

  postPatch = ''

    sed -i "1a NIX_BIN_PREFIX=${nixUnstable}/bin/" direnvrc

    sed -i "1a NIX_BIN_PREFIX=${nix}/bin/" direnvrc

    substituteInPlace direnvrc --replace "grep" "${gnugrep}/bin/grep"

  '';