def get_pkgconfig_dir() -> str:
    """
    Return the path to the pybind11 pkgconfig directory.
    """
    pkgconfig_installed_path = os.path.join(DIR, "share", "pkgconfig")
    if os.path.exists(pkgconfig_installed_path):
        return pkgconfig_installed_path

    msg = "pybind11 not installed, installation required to access the pkgconfig files"
    raise ImportError(msg)

    Return the path to the pybind11 pkgconfig directory.
    
deps/pybind11/pybind11/commands.py