.........................................................................................................E.
======================================================================
ERROR: test_signs_and_verifies (dkim.tests.test_arc.TestSignAndVerify)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/build/python-dkim/src/dkimpy-1.0.5/dkim/__init__.py", line 1012, in sign
    AuthenticationResultsHeader
NameError: name 'AuthenticationResultsHeader' is not defined

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/build/python-dkim/src/dkimpy-1.0.5/dkim/tests/test_arc.py", line 74, in test_signs_and_verifies
    sig_lines = dkim.arc_sign(
  File "/build/python-dkim/src/dkimpy-1.0.5/dkim/__init__.py", line 1398, in arc_sign
    return a.sign(selector, domain, privkey, srv_id, include_headers=include_headers,
  File "/build/python-dkim/src/dkimpy-1.0.5/dkim/__init__.py", line 1015, in sign
    raise AuthresNotFoundError
dkim.AuthresNotFoundError

----------------------------------------------------------------------
Ran 107 tests in 0.783s

FAILED (errors=1)
==> ERROR: A failure occurred in check().
    Aborting...