Set self.state_machine to None for terminal states #198
Description
The next issue is with the plumpy state, which is cyclic since the Process keeps a reference of the state and the state keeps a reference of the Process:
In [19]: from plumpy.process_states import State
In [20]: states = [o for o in all_objects if hasattr(o, "__class__") and isinstance(o, State)]
...: states
Out[20]: [<plumpy.process_states.Finished at 0x7f56a01f5ac0>]
In [21]: f = states[0]
In [22]: f.__dict__
Out[22]:
{'state_machine': <aiida_sleep.sleep_job.SleepCalculation at 0x7f56a04f55e0>,
'in_state': True,
'result': ExitCode(status=0, message=None, invalidates_cache=False),
'successful': True,
'_called': 0,
'state': None}
In [23]: f.state_machine._state
Out[23]: <plumpy.process_states.Finished at 0x7f56a01f5ac0>Originally posted by @chrisjsewell in aiidateam/aiida-core#4603 (comment)