slash.add_error fails on TypeError when it outside test scope

[ayalash]

Failure Traceback:

Session error caught -- TypeError: issubclass() arg 1 must be a class

[2017-12-03 10:33:34] Unexpected error occurred
Traceback (most recent call last):
  File "/home/ayalas/src/github/slash/slash/frontend/slash_run.py", line 68, in slash_run
    run_tests(collected)
  File "/usr/lib/python3.6/contextlib.py", line 88, in __exit__
    next(self.gen)
  File "/home/ayalas/src/github/slash/slash/core/session.py", line 133, in get_started_context
    hooks.session_end()  # pylint: disable=no-member
  File "/home/ayalas/virtualenvs/env3.6/lib/python3.6/site-packages/gossip/hooks.py", line 92, in __call__
    return self.trigger(kwargs)
  File "/home/ayalas/virtualenvs/env3.6/lib/python3.6/site-packages/gossip/hooks.py", line 213, in trigger
    break
  File "/usr/lib/python3.6/contextlib.py", line 88, in __exit__
    next(self.gen)
  File "/home/ayalas/virtualenvs/env3.6/lib/python3.6/site-packages/gossip/exception_policy.py", line 18, in context
    self._handle_trigger_end(ctx)
  File "/home/ayalas/virtualenvs/env3.6/lib/python3.6/site-packages/gossip/exception_policy.py", line 36, in _handle_trigger_end
    reraise(exc_type, exc_value, exc_tb)
  File "/home/ayalas/virtualenvs/env3.6/lib/python3.6/site-packages/gossip/_compat.py", line 54, in reraise
    raise value
  File "/home/ayalas/virtualenvs/env3.6/lib/python3.6/site-packages/gossip/hooks.py", line 222, in _call_registration
    registration(**kwargs)
  File "/home/ayalas/virtualenvs/env3.6/lib/python3.6/site-packages/gossip/registration.py", line 75, in __call__
    return self.func(*args, **kwargs)
  File "/tmp/testme.py", line 7, in _callback
    add_error('session: add_error')
  File "/home/ayalas/src/github/slash/slash/utils/__init__.py", line 52, in add_error
    return context.session.results.current.add_error(msg, frame_correction=frame_correction+1, exc_info=exc_info)
  File "/home/ayalas/src/github/slash/slash/core/result.py", line 204, in add_error
    context.reporter.report_test_error_added(context.test, err)
  File "/home/ayalas/src/github/slash/slash/reporting/console_reporter.py", line 385, in report_test_error_added
    self._report_test_error_failure_added(test, error, 'E')
  File "/home/ayalas/src/github/slash/slash/reporting/console_reporter.py", line 392, in _report_test_error_failure_added
    if not issubclass(e.exception_type, CLI_ABORT_EXCEPTIONS):
TypeError: issubclass() arg 1 must be a class
ERROR: Unexpected error: issubclass() arg 1 must be a class

Reproduces by:

from stokado.io.utils import report_exception
from slash import add_error, hooks

@hooks.session_end.register
def _callback():
     add_error('session: add_error')
 
def test_a():
    pass