bitbake --observe-only is supposed to capture and display events sent by the server, but it doesn't seem to be working. If I start it before running bitbake to build something, it exits when the build starts with the following error:

----------- snip -----------
$ BBSERVER=localhost:-1 bitbake --observe-only
Traceback (most recent call last):
  File "/home/paul/poky/poky/bitbake/bin/bitbake", line 48, in <module>
    cookerdata.CookerConfiguration()))
  File "/home/paul/poky/poky/bitbake/lib/bb/main.py", line 511, in bitbake_main
    configParams)
  File "/home/paul/poky/poky/bitbake/lib/bb/ui/knotty.py", line 343, in main
    includelogs, loglines, consolelogfile = _log_settings_from_server(server)
  File "/home/paul/poky/poky/bitbake/lib/bb/ui/knotty.py", line 328, in _log_settings_from_server
    raise BaseException(error)
BaseException: Not able to execute not readonly commands in readonly mode
----------- snip -----------

If I instead run it after I start the bitbake build, it times out:

----------- snip -----------
$ BBSERVER=localhost:-1 bitbake --observe-only
Traceback (most recent call last):
  File "/home/paul/poky/poky/bitbake/bin/bitbake", line 48, in <module>
    cookerdata.CookerConfiguration()))
  File "/home/paul/poky/poky/bitbake/lib/bb/main.py", line 496, in bitbake_main
    server_connection.setupEventQueue()
  File "/home/paul/poky/poky/bitbake/lib/bb/server/xmlrpc.py", line 337, in setupEventQueue
    self.events = uievent.BBUIEventQueue(self.connection, self.clientinfo)
  File "/home/paul/poky/poky/bitbake/lib/bb/ui/uievent.py", line 72, in __init__
    raise Exception(errmsg)
Exception: Could not register UI event handler. Error: Cooker is busy: running, host 127.0.0.1, port 34833
WARNING: Could not register UI event handler. Error: Cooker is busy: running, host 127.0.0.1, port 34833, retry
WARNING: Could not register UI event handler. Error: Cooker is busy: running, host 127.0.0.1, port 34833, retry
WARNING: Could not register UI event handler. Error: Cooker is busy: running, host 127.0.0.1, port 34833, retry
WARNING: Could not register UI event handler. Error: Cooker is busy: running, host 127.0.0.1, port 34833, retry
WARNING: Could not register UI event handler. Error: Cooker is busy: running, host 127.0.0.1, port 34833, retry
----------- snip -----------