`follow_tcp_stream` (and flow tracing in general) doesn't work

[Toby]

Describe the bug

def main():
    try:
        streams = follow_tcp_stream(fin="test.pcap")
    except Exception as e:
        traceback.print_exc()
        return

Traceback (most recent call last):
  File "c:\Users\tobyx\Desktop\prox\main.py", line 51, in main
    streams = follow_tcp_stream(fin="test.pcap")
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\interface\misc.py", line 80, in follow_tcp_stream
    extraction = Extractor(fin=fin, fout=None, format=None, auto=True, extension=extension,
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\foundation\extraction.py", line 812, in __init__
    self.run()    # start extraction
    ^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\foundation\extraction.py", line 448, in run
    self.record_frames()
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\foundation\extraction.py", line 599, in record_frames
    self._exeng.read_frame()
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\foundation\engines\pcap.py", line 175, in read_frame
    ext._trace.tcp(data_tf_tcp)
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\foundation\traceflow\traceflow.py", line 336, in __call__
    self.dump(packet)
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\foundation\traceflow\tcp.py", line 59, in dump
    output = self.trace(packet, output=True)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\foundation\traceflow\tcp.py", line 112, in trace
    fpout=self._foutio(fname=f'{self._fproot}/{label}{self._fdpext or ""}', protocol=packet.protocol,
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\dumpkit\pcap.py", line 70, in __init__
    super().__init__(fname, protocol=protocol, byteorder=byteorder, nanosecond=nanosecond, **kwargs)
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\dictdumper\dumper.py", line 168, in __init__
    self._dump_header(**kwargs)  # initialise output file
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\dumpkit\pcap.py", line 103, in _dump_header
    packet = Header(
             ^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\protocols\protocol.py", line 520, in __init__
    self.__post_init__(file, length, **kwargs)  # type: ignore[arg-type]
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\protocols\misc\pcap\header.py", line 261, in __post_init__
    _data = self.pack(**kwargs)
            ^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\protocols\protocol.py", line 259, in pack
    return self.__header__.pack(packet)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\protocols\schema\schema.py", line 544, in pack
    temp = field.pack(value, packet)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\tobyx\Desktop\prox\venv\Lib\site-packages\pcapkit\corekit\fields\field.py", line 185, in pack
    return struct.pack(self.template, pre_processed)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
struct.error: argument for 's' must be a bytes object

System information
A clear and concise description of your system information.

• OS Version: Windows 11
• Python Version: 3.11.6 (tried 3.9, same)
• Python Implementation: CPython

Traceback stack
Already did

Expected behavior
Doesn't crash and performs as expected.

Additional context
N/A

[Jarry Shaw]

Could you please provide the test.pcap file that you're using?