Error generating py3o document

[tonthon]

  File "/usr/lib64/python3.8/zipfile.py", line 1816, in writestr
    with self.open(zinfo, mode='w') as dest:
  File "/usr/lib64/python3.8/zipfile.py", line 1517, in open
    return self._open_to_write(zinfo, force_zip64=force_zip64)
  File "/usr/lib64/python3.8/zipfile.py", line 1614, in _open_to_write
    self.fp.write(zinfo.FileHeader(zip64))
TypeError: string argument expected, got 'bytes'
Exception ignored in: <function ZipFile.__del__ at 0x7f88eff1bc10>
Traceback (most recent call last):
  File "/usr/lib64/python3.8/zipfile.py", line 1821, in __del__
    self.close()
  File "/usr/lib64/python3.8/zipfile.py", line 1839, in close
    self._write_end_record()
  File "/usr/lib64/python3.8/zipfile.py", line 1943, in _write_end_record
    self.fp.write(endrec)
TypeError: string argument expected, got 'bytes'