Windows stacktraces on msgpack on Carbon

[UtahDave]

Description of Issue/Question

Windows stacktraces on msgpack

Setup

Install Salt from carbon branch on Windows

Steps to Reproduce Issue

<-- snip -->>
[DEBUG   ] Minion of "test.test" is handling event tag 'salt/auth/creds'
[CRITICAL] Could not deserialize msgpack message.This often happens when trying to read a file not in binary modeTo see message payload, enable debug logging and retry. Exception: Unpack failed: error = 0
[INFO    ] Returning information for job: 20160906180748572256
[[DEBUG   ] Initializing new AsyncZeroMQReqChannel for ('c:\\salt\\conf\\pki\\minion', 'davewintest', 'tcp://192.xxx.xxx.xxx:4506', 'aes')
DEBUG   ] Msgpack deserialization failure on message:
[DEBUG   ] Initializing new AsyncAuth for ('c:\\salt\\conf\\pki\\minion', 'davewintest', 'tcp://192.xxx.xxx.xxx:4506')
[ERROR   ] Exception in callback <functools.partial object at 0x00000000067A5408>
Traceback (most recent call last):
  File "C:\salt\bin\lib\site-packages\tornado\ioloop.py", line 600, in _run_callback
    ret = callback()
  File "C:\salt\bin\lib\site-packages\tornado\stack_context.py", line 275, in null_wrapper
    return fn(*args, **kwargs)
  File "C:\salt\bin\lib\site-packages\tornado\ioloop.py", line 615, in <lambda>
    self.add_future(ret, lambda f: f.result())
  File "C:\salt\bin\lib\site-packages\tornado\concurrent.py", line 232, in result
    raise_exc_info(self._exc_info)
  File "C:\salt\bin\lib\site-packages\tornado\gen.py", line 1014, in run
    yielded = self.gen.throw(*exc_info)
  File "C:\salt\bin\lib\site-packages\salt\minion.py", line 757, in handle_event
    yield [minion.handle_event(package) for minion in self.minions]
  File "C:\salt\bin\lib\site-packages\tornado\gen.py", line 1008, in run
    value = future.result()
  File "C:\salt\bin\lib\site-packages\tornado\concurrent.py", line 232, in result
    raise_exc_info(self._exc_info)
  File "C:\salt\bin\lib\site-packages\tornado\gen.py", line 789, in callback
    result_list.append(f.result())
  File "C:\salt\bin\lib\site-packages\tornado\concurrent.py", line 232, in result
    raise_exc_info(self._exc_info)
  File "C:\salt\bin\lib\site-packages\tornado\gen.py", line 282, in wrapper
    yielded = next(result)
  File "C:\salt\bin\lib\site-packages\salt\minion.py", line 1988, in handle_event
    mtag, data = salt.utils.event.MinionEvent.unpack(tag)
  File "C:\salt\bin\lib\site-packages\salt\utils\event.py", line 402, in unpack
    data = serial.loads(mdata)
  File "C:\salt\bin\lib\site-packages\salt\payload.py", line 137, in loads
    ret = msgpack.loads(msg, use_list=True, encoding=encoding)
  File "msgpack/_unpacker.pyx", line 146, in msgpack._unpacker.unpackb (msgpack/_unpacker.cpp:146)
UnpackValueError: Unpack failed: error = 0
[DEBUG   ] Initializing new AsyncZeroMQReqChannel for ('c:\\salt\\conf\\pki\\minion', 'davewintest', 'tcp://192.xxx.xxx.xxx:4506', 'clear')

Salt does seem to continue to work.

Versions Report

Carbon