if has nix; then
    if ! has nix_direnv_version || ! nix_direnv_version 2.1.1; then
        source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/2.1.1/direnvrc" \
            "sha256-b6qJ4r34rbE23yWjMqbmu3ia2z4b2wIlZUksBke/ol0="
    fi
    nix_direnv_watch_file ../shell.nix
    use flake ..
fi