ResourceWarning for unclosed filestream on svd_data.zip

[edcloudcycle]

Hi.
Installed the latest version today and noticed something I hadn't seen before. Maybe not due to an update but perhaps a change in where the default pack comes from on my setup.

sys:1: ResourceWarning: unclosed file <_io.BufferedReader name='C:\\WorkingDir\\tm_fct_calibration\\.venv\\Lib\\site-packages\\pyocd\\debug\\svd\\svd_data.zip'>
ResourceWarning: Enable tracemalloc to get the object allocation traceback

Looking into it when a board is created as part of a session and the memory map is created a zip stream seems to be made here:

class SVDFile(object):
    @classmethod

    def from_builtin(cls, svd_name):

        try:
            zip_ref = importlib_resources.files("pyocd").joinpath(BUILTIN_SVD_DATA_PATH)
            zip_stream = zip_ref.open('rb')
            zip = zipfile.ZipFile(zip_stream, 'r')
            return SVDFile(zip.open(svd_name))
        except (KeyError, FileNotFoundError, zipfile.BadZipFile) as err:
            from ...core.session import Session
            LOG.warning("unable to open builtin SVD file: %s", err, exc_info=Session.get_current().log_tracebacks)
            return None

But it is not clear to me where this reference is closed so maybe that is what generates the warning. I can see the session is closed when my application exits. My usage is:

with ConnectHelper.session_with_chosen_probe(blocking=False) as session:

            board = session.board
            target = board.target
            flash = target.memory_map.get_boot_memory()

            # Load firmware into device.
            FileProgrammer(session).program(filename)

            # Flash a single phrase without erasing to set the serial number
            flasher = Flash(target, flash.algo)
            flasher.region = flash
            flasher.init(operation=Flash.Operation.PROGRAM)

            flasher.program_phrase(address=0x10001080, bytes=[serial_lsb, serial_msb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff])

            # Reset, run.
            target.reset_and_halt()
            target.resume()

Thanks

Ed