b'-\xff'.decode(sys.getfilesystemencoding(), 'surrogateescape')

'-\udcff'

Traceback (most recent call last):
  File "/RustPython/vm/pylib-crate/Lib/_codecs.py", line 567, in lookup_error
    err_handler = codec_error_registry[errors]
KeyError: surrogateescape

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/RustPython/vm/pylib-crate/Lib/_codecs.py", line 140, in decode
    res = codec[1](obj, errors)
  File "/RustPython/vm/pylib-crate/Lib/encodings/utf_8.py", line 16, in decode
    return codecs.utf_8_decode(input, errors, True)
  File "/RustPython/vm/pylib-crate/Lib/_codecs.py", line 463, in __call__
    return self._f(*args, **kwargs)
  File "/RustPython/vm/pylib-crate/Lib/_codecs.py", line 177, in utf_8_decode
    res, consumed = PyUnicode_DecodeUTF8Stateful(data, len(data), errors, final)
  File "/RustPython/vm/pylib-crate/Lib/_codecs.py", line 1133, in PyUnicode_DecodeUTF8Stateful
    s,  startinpos, endinpos)
  File "/RustPython/vm/pylib-crate/Lib/_codecs.py", line 1059, in unicode_call_errorhandler
    errorHandler = lookup_error(errors)
  File "/RustPython/vm/pylib-crate/Lib/_codecs.py", line 569, in lookup_error
    raise LookupError("unknown error handler name %s"%errors)
LookupError: unknown error handler name surrogateescape