bitbake$ bitbake-hashserv -l DEBUG -b localhost:0
start_tcp handle_client <bound method AsyncServer.handle_client of <hashserv.server.Server object at 0x7f85fefdc5b0>>, host localhost, port 0
server_coro <coroutine object start_server at 0x7f85fed408c0>
Traceback (most recent call last):
  File "/OE/nodistro/honister/bitbake/lib/bb/asyncrpc/serv.py", line 148, in start_tcp
    self.server = self.loop.run_until_complete(server_coro)
  File "/usr/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
    return future.result()
  File "/usr/lib/python3.8/asyncio/streams.py", line 94, in start_server
    return await loop.create_server(factory, host, port, **kwds)
  File "/usr/lib/python3.8/asyncio/base_events.py", line 1463, in create_server
    raise OSError(err.errno, 'error while attempting '
OSError: [Errno 99] error while attempting to bind on address ('::1', 0, 0, 0): cannot assign requested address

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/OE/nodistro/honister/bitbake/bin/bitbake-hashserv", line 59, in <module>
    ret = main()
  File "/OE/nodistro/honister/bitbake/bin/bitbake-hashserv", line 53, in main
    server.serve_forever()
  File "/OE/nodistro/honister/bitbake/lib/bb/asyncrpc/serv.py", line 245, in serve_forever
    self.start()
  File "/OE/nodistro/honister/bitbake/lib/bb/asyncrpc/serv.py", line 151, in start_tcp
    except Error as e:
NameError: name 'Error' is not defined