cirq.StateVectorSimulatorState removed

[maffoo]

Unable to import qsimcirq with latest versions of cirq, due to cirq.StateVectorSimulatorState being removed:

  File "/usr/local/google/home/maffoo/.virtualenvs/pyle/lib/python3.8/site-packages/qsimcirq/__init__.py", line 56, in <module>
    from .qsim_simulator import (
  File "/usr/local/google/home/maffoo/.virtualenvs/pyle/lib/python3.8/site-packages/qsimcirq/qsim_simulator.py", line 27, in <module>
    class QSimSimulatorState(cirq.StateVectorSimulatorState):
AttributeError: module 'cirq' has no attribute 'StateVectorSimulatorState'

[95-martin-orion]

Yup, pip install cirq --pre is going to be pretty unstable for a bit while Cirq 1.0 changes rush in. qsim hasn't released a patch for 1.0 (in no small part because of how many deprecations are going through) so for now you should fall back to stable Cirq (no --pre)

[95-martin-orion]

Duplicate of #543