TypeError: __init__() missing 3 required positional arguments: 'type', 'value', and 'context'

I have a tox.ini for my project like this:

```
[testenv:yapf-inplace]
description = Run yapf and edit all files in place
skip_install = True
deps = yapf==0.16.1
commands = yapf --in-place --recursive --parallel obs/ tests/
```

And when I run it, I get this:
```
GLOB sdist-make: /Users/daenyth/Curata/observer/setup.py
yapf-inplace create: /Users/daenyth/Curata/observer/.tox/yapf-inplace
yapf-inplace installdeps: yapf==0.16.1
yapf-inplace installed: appdirs==1.4.3,packaging==16.8,pyparsing==2.2.0,six==1.10.0,yapf==0.16.1
yapf-inplace runtests: PYTHONHASHSEED='1449245045'
yapf-inplace runtests: commands[0] | yapf --in-place --recursive --parallel obs/ tests/
Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/threading.py", line 916, in _bootstrap_inner
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/threading.py", line 864, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 272, in _queue_management_worker
result_item = reader.recv()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/connection.py", line 251, in recv
return _ForkingPickler.loads(buf.getbuffer())
TypeError: __init__() missing 3 required positional arguments: 'type', 'value', and 'context'

```

At that point it hangs, and if I ctrl+c I get this:

long stack trace

```
^CProcess Process-4:
Process Process-6:
Process Process-5:
Process Process-7:
Process Process-8:
ERROR: KEYBOARDINTERRUPT
Process Process-3:
Traceback (most recent call last):
File "/Users/daenyth/Curata/observer/.tox/yapf-inplace/bin/yapf", line 11, in
Process Process-2:
sys.exit(run_main())
File "/Users/daenyth/Curata/observer/.tox/yapf-inplace/lib/python3.6/site-packages/yapf/__init__.py", line 296, in run_main
Process Process-1:
sys.exit(main(sys.argv))
File "/Users/daenyth/Curata/observer/.tox/yapf-inplace/lib/python3.6/site-packages/yapf/__init__.py", line 188, in main
Traceback (most recent call last):
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 169, in _prTraceback (most recent call last):
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 169, in _process_worker
call_item = call_queue.get(block=True)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/queues.py", line 93, in get
with self._rlock:
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/synchronize.py", line 96, in __enter__
return self._semlock.__enter__()
KeyboardInterrupt
Traceback (most recent call last):
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 169, in _process_worker
call_item = call_queue.get(block=True)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/queues.py", line 93, in get
with self._rlock:
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/synchronize.py", line 96, in __enter__
return self._semlock.__enter__()
Traceback (most recent call last):
KeyboardInterrupt
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 169, in _process_worker
call_item = call_queue.get(block=True)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/queues.py", line 93, in get
with self._rlock:
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/synchronize.py", line 96, in __enter__
return self._semlock.__enter__()
Traceback (most recent call last):
KeyboardInterrupt
Traceback (most recent call last):
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 169, in _process_worker
call_item = call_queue.get(block=True)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/queues.py", line 94, in get
res = self._recv_bytes()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/connection.py", line 216, in recv_bytes
buf = self._recv_bytes(maxlength)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/connection.py", line 407, in _recv_bytes
buf = self._recv(4)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/connection.py", line 379, in _recv
chunk = read(handle, remaining)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
KeyboardInterrupt
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 169, in _process_worker
call_item = call_queue.get(block=True)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/queues.py", line 93, in get
with self._rlock:
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/synchronize.py", line 96, in __enter__
return self._semlock.__enter__()
Traceback (most recent call last):
KeyboardInterrupt
Traceback (most recent call last):
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 169, in _process_worker
call_item = call_queue.get(block=True)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/queues.py", line 93, in get
with self._rlock:
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/synchronize.py", line 96, in __enter__
return self._semlock.__enter__()
KeyboardInterrupt
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/process.py", line 169, in _process_worker
call_item = call_queue.get(block=True)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/queues.py", line 93, in get
with self._rlock:
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/synchronize.py", line 96, in __enter__
return self._semlock.__enter__()
KeyboardInterrupt
ocess_worker
call_item = call_queue.get(block=True)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/queues.py", line 93, in get
with self._rlock:
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/multiprocessing/synchronize.py", line 96, in __enter__
return self._semlock.__enter__()
KeyboardInterrupt
parallel=args.parallel)
File "/Users/daenyth/Curata/observer/.tox/yapf-inplace/lib/python3.6/site-packages/yapf/__init__.py", line 231, in FormatFiles
for future in concurrent.futures.as_completed(future_formats):
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/_base.py", line 215, in as_completed
waiter.event.wait(wait_timeout)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/threading.py", line 551, in wait
signaled = self._cond.wait(timeout)
File "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/threading.py", line 295, in wait
waiter.acquire()
KeyboardInterrupt
ERROR: keyboardinterrupt
```