Issue with SxI.header_format = 'HEADER_LEN_BYTE'

[thats-i-t]

Python 3.13.7
pyxcp==0.23.9

With mwe_bug_config.py

c = get_config()  # noqa

c.Transport.layer = 'SXI'
c.Transport.SxI.bitrate = 115200
c.Transport.SxI.bytesize = 8
c.Transport.SxI.port = 'COM13'
c.Transport.SxI.header_format = 'HEADER_LEN_BYTE

and mwe_bug.py

from pyxcp.cmdline import ArgumentParser

ap = ArgumentParser(description="pyXCP SXI test" ) 

with ap.run() as xcp:
    xcp.connect()
    print("Connected to XCP slave.")
    print("Slave ID:", xcp.identifier(0x01))
    print("Properties:", xcp.slaveProperties)
    xcp.disconnect()

and

python mwe_bug.py --config mwe_bug_config.py

I get

error: pack expected 1 items for packing (got 2)

resp.

..\pyxcp2\venv\Lib\site-packages\pyxcp\transport\base.py:330 in _prepare_request │
│ │
│ 327 │ │ else: │
│ 328 │ │ │ packet = bytes(flatten(cmd_bytes, data)) │
│ 329 │ │ │
│ ❱ 330 │ │ header = self.HEADER.pack(len(packet), self.counter_send) │
│ 331 │ │ self.counter_send = (self.counter_send + 1) & 0xFFFF │
│ 332 │ │ │
│ 333 │ │ frame = header + packet

where

len(packet) == 2
and self.HEADER == struct.Struct(f"<B")
and self.counter_send = 0

with full requirements.txt:

bandit==1.8.6
chardet==5.2.0
colorama==0.4.6
construct==2.10.70
line-profiler-pycharm==1.2.0
line_profiler==5.0.0
Mako==1.3.10
markdown-it-py==4.0.0
MarkupSafe==3.0.2
mdurl==0.1.2
packaging==25.0
Pygments==2.19.2
pyserial==3.5
python-can==4.6.1
pytz==2025.2
pyusb==1.3.1
pyxcp==0.23.9
PyYAML==6.0.2
rich==14.1.0
stevedore==5.5.0
toml==0.10.2
tomlkit==0.13.3
traitlets==5.11.2
typing_extensions==4.15.0
uptime==3.0.1
wrapt==1.17.3

[christoph2]

@thats-i-t
The next release will include much-improved framing code.