Traceback tells:

#22 0x00000000005a52db in PyInterpreterState_Clear (interp=0x95ac80) at ../Python/pystate.c:111
    Py_CLEAR(interp->sysdict);

While cleaning up interp->sysdict...

#19 0x00000000004d86c6 in tb_dealloc.46270 (tb=0x7f0aa1278f38) at ../Python/traceback.c:28
#20 0x00000000004d87e1 in tb_dealloc.46270 (tb=0x7f0aa1278ea8) at ../Python/traceback.c:27

Removing some traceback from sysdict. Maybe, sys.exc_traceback.

#17 0x00000000004c56e7 in subtype_dealloc.25650 (
    self=<ClientConnectionJob(daemon=<Daemon(_Daemon__mustshutdown=<_Event(_Verbose__verbose=False, _Event__flag=True, _Event__cond=<_Condition(_Verbose__verbose=False, _Condition__lock=<thread.lock at remote 0x7f0a9f759790>, acquire=<built-in method acquire of thread.lock object at remote 0x7f0a9f759790>, _Condition__waiters=[], release=<built-in method release of thread.lock object at remote 0x7f0a9f759790>) at remote 0x7f0a9e9241d0>) at remote 0x7f0a9e924190>, objectsById={'root': <RootService(_scheduler=<Scheduler(_lock=<thread.lock at remote 0x7f0aa1211d50>, _operations={'cookie_9de0e8d93ed84452a1ce8cc92268979e': <Operation(_exception=None, _result='obj_450f0972022e41b2b7c1f29f49bdca83', _action=<function at remote 0x7f0a9f7b89b0>, _lock=<_RLock(_Verbose__verbose=False, _RLock__owner=None, _RLock__block=<thread.lock at remote 0x7f0a9f759370>, _RLock__count=0) at remote 0x7f0a9e936190>, _started_at=<float at remote 0xab90f8>, cookie='cookie_9de0e8d93ed84452a1ce8cc92268979e', _complete=<_Condition(_Condition__lock=...(truncated)) at ../Objects/typeobject.c:1035
#18 0x0000000000534b93 in frame_dealloc.14921 (f=Frame 0x7f0a9f6d49d8, for file /etc/remoting/remoting_agent.zip/Pyro4/socketserver/threadpool.py, line 39, in run ())
    at ../Objects/frameobject.c:458

Removing frame object owned by the traceback.

...

#7  PyEval_EvalFrameEx (f=f@entry=Frame 0x7f0a40000b50, for file /etc/remoting/remoting_agent.zip/Pyro4/socketutil.py, line 453, in __del__ (self=<SocketConnection at remote 0x7f0a9e924510>),
    throwflag=throwflag@entry=0) at ../Python/ceval.c:2987
#4  PyEval_EvalFrameEx (f=f@entry=Frame 0x7f0a9e929b60, for file /etc/remoting/remoting_agent.zip/Pyro4/socketutil.py, line 463, in close (self=<SocketConnection at remote 0x7f0a9e924510>),
    throwflag=throwflag@entry=0) at ../Python/ceval.c:3251

Calling SocketConnection.__del__.  It calls SocketConnection.close.

#3  0x000000000055acc0 in set_exc_info (tb=<traceback at remote 0x7f0aa1232878>, value=exceptions.AttributeError("'NoneType' object has no attribute 'SHUT_RDWR'",),
    type=<type at remote 0x920ce0>, tstate=0x95ad10) at ../Python/ceval.c:3736

SocketConnection.close raise AttributeError.

#2  PySys_SetObject (name=name@entry=0x61d02a "exc_type", v=v@entry=<type at remote 0x920ce0>) at ../Python/sysmodule.c:83

Trying to register the exception to sys.

#0  PyDict_SetItem (op=op@entry=0x0, key=key@entry='exc_type', value=value@entry=<type at remote 0x920ce0>) at ../Objects/dictobject.c:832

But interp->sysdict is NULL already.