Ticket #163 (new defect)

Description

I have the following traceback when firing a ShellCommand on a slave at 0.7.3, master at 0.7.6:

2007/12/29 06:46 EST [-] SlaveBuilder.commandComplete <buildbot.slave.commands.SlaveShellCommand instance at 0x859682c>
2007/12/29 06:46 EST [Broker,client]  startCommand:shell [id 671]
2007/12/29 06:46 EST [Broker,client] SlaveBuilder.commandFailed <buildbot.slave.commands.SlaveShellCommand instance at 0x860cf
ac>
2007/12/29 06:46 EST [Broker,client] Traceback (most recent call last):
          File "/usr/local/lib/python2.4/site-packages/twisted/spread/pb.py", line 870, in proto_message
            self._recvMessage(self.localObjectForID, requestID, objectID, message, answerRequired, netArgs, netKw)
          File "/usr/local/lib/python2.4/site-packages/twisted/spread/pb.py", line 884, in _recvMessage
            netResult = object.remoteMessageReceived(self, message, netArgs, netKw)
          File "/usr/local/lib/python2.4/site-packages/twisted/spread/flavors.py", line 119, in remoteMessageReceived
            state = method(*args, **kw)
          File "/usr/local/lib/python2.4/site-packages/buildbot/slave/bot.py", line 170, in remote_startCommand
            d = defer.maybeDeferred(self.command.start)
        --- <exception caught here> ---
          File "/usr/local/lib/python2.4/site-packages/twisted/internet/defer.py", line 107, in maybeDeferred
            result = f(*args, **kw)
          File "/usr/local/lib/python2.4/site-packages/buildbot/slave/commands.py", line 544, in start
            assert args['workdir'] is not None
        exceptions.AssertionError:

It was fixed by updating the client to 0.7.6. It seems there is now a default value of workdir, but I didn't try further.