The test does not fails but outputs the following erroneous logs:

  ERROR    root:message_bus.py:1194 add match request failed. match="sender='org.freedesktop.DBus',interface='org.freedesktop.DBus',path='/org/freedesktop/DBus',member='NameOwnerChanged'",
  WARNING  root:message_bus.py:584 a message handler threw an exception on shutdown
  Traceback (most recent call last):
    File "/home/mocramis/misc/dbus-fast/src/dbus_fast/aio/message_reader.py", line 22, in _message_reader
      message = unmarshaller._unmarshall()
    File "/home/mocramis/misc/dbus-fast/src/dbus_fast/_private/unmarshaller.py", line 742, in _unmarshall
      self._read_header()
    File "/home/mocramis/misc/dbus-fast/src/dbus_fast/_private/unmarshaller.py", line 611, in _read_header
      self._read_to_pos(HEADER_SIGNATURE_SIZE)
    File "/home/mocramis/misc/dbus-fast/src/dbus_fast/_private/unmarshaller.py", line 366, in _read_to_pos
      self._read_sock_without_fds(pos)
    File "/home/mocramis/misc/dbus-fast/src/dbus_fast/_private/unmarshaller.py", line 329, in _read_sock_without_fds
      raise EOFError()
  EOFError

  During handling of the above exception, another exception occurred:

  Traceback (most recent call last):
    File "/home/mocramis/misc/dbus-fast/src/dbus_fast/message_bus.py", line 582, in _finalize
      handler(None, err)
    File "/home/mocramis/misc/dbus-fast/src/dbus_fast/message_bus.py", line 737, in _reply_notify
      callback(reply, err)
    File "/home/mocramis/misc/dbus-fast/src/dbus_fast/message_bus.py", line 1197, in add_match_notify
      if msg.message_type == MessageType.ERROR:
  AttributeError: 'NoneType' object has no attribute 'message_type'

However, trying to capture those logs seems to prevent the race
condition from happening. Therefore, we just run the test for coverage.

previous added test pushed the testsuite above 5s on py38 ant py39/

This is especially common as BaseMessageBus._finalize calls handler(None, err)
when an exception is raised.

…cramis/dbus-fast into notify_callback_empty_message