TFTP into MAAS server from localhost causes unhandled error

I can't reproduce this. Can you try logging the value at line 105 in provisioningserver/boot/__init__.py:

    log.msg("remote=%r" % (get("remote", "<not set>"),))

Here you go; I guess that's not what you expected?

2015-02-03 10:33:49-0600 [-] remote=('::1', 50809, 0, 0)
2015-02-03 10:33:49-0600 [-] remote=('::1', 50809, 0, 0)
2015-02-03 10:33:49-0600 [-] Unhandled error in Deferred:
2015-02-03 10:33:49-0600 [-] Unhandled Error
        Traceback (most recent call last):
          File "/usr/lib/python2.7/dist-packages/tftp/protocol.py", line 67, in _startSession
            context, self.backend.get_reader, datagram.filename)
          File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 118, in callWithContext
            return self.currentContext().callWithContext(ctx, func, *args, **kw)
          File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 81, in callWithContext
            return func(*args,**kw)
          File "/usr/lib/python2.7/dist-packages/provisioningserver/utils/twisted.py", line 62, in wrapper
            return maybeDeferred(func, *args, **kwargs)
        --- <exception caught here> ---
          File "/usr/lib/python2.7/dist-packages/twisted/internet/defer.py", line 139, in maybeDeferred
            result = f(*args, **kw)
          File "/usr/lib/python2.7/dist-packages/provisioningserver/pserv_services/tftp.py", line 216, in get_reader
            mac_address = get_remote_mac()
          File "/usr/lib/python2.7/dist-packages/provisioningserver/boot/__init__.py", line 108, in get_remote_mac
            remote_host, remote_port = get("remote", (None, None))
        exceptions.ValueError: too many values to unpack