flingbot AttributeError: module 'typing' has no attribute '

When I run python run_sim.py --eval --tasks flingbot-normal-rect-eval.hdf5 --load flingbot.pth --num_processes 1 --gui there is a problem :

Traceback (most recent call last): File "run_sim.py", line 1, in from utils import ( File "/media/randy/299D817A2D97AD94/fty/flingbot/utils.py", line 2, in from environment import SimEnv, TaskLoader File "/media/randy/299D817A2D97AD94/fty/flingbot/environment/init.py", line 1, in from .simEnv import SimEnv File "/media/randy/299D817A2D97AD94/fty/flingbot/environment/simEnv.py", line 3, in from .utils import ( File "/media/randy/299D817A2D97AD94/fty/flingbot/environment/utils.py", line 1, in from torch import cat, tensor File "/home/randy/anaconda3/envs/flingbot/lib/python3.6/site-packages/torch/init.py", line 643, in from .functional import * # noqa: F403 File "/home/randy/anaconda3/envs/flingbot/lib/python3.6/site-packages/torch/functional.py", line 6, in import torch.nn.functional as F File "/home/randy/anaconda3/envs/flingbot/lib/python3.6/site-packages/torch/nn/init.py", line 1, in from .modules import * # noqa: F403 File "/home/randy/anaconda3/envs/flingbot/lib/python3.6/site-packages/torch/nn/modules/init.py", line 2, in from .linear import Identity, Linear, Bilinear, LazyLinear File "/home/randy/anaconda3/envs/flingbot/lib/python3.6/site-packages/torch/nn/modules/linear.py", line 6, in from .. import functional as F File "/home/randy/anaconda3/envs/flingbot/lib/python3.6/site-packages/torch/nn/functional.py", line 11, in from .._jit_internal import boolean_dispatch, _overload, BroadcastingList1, BroadcastingList2, BroadcastingList3 File "/home/randy/anaconda3/envs/flingbot/lib/python3.6/site-packages/torch/_jit_internal.py", line 34, in from typing_extensions import Final File "/home/randy/anaconda3/envs/flingbot/lib/python3.6/site-packages/typing_extensions.py", line 159, in class _FinalForm(typing._SpecialForm, _root=True): AttributeError: module 'typing' has no attribute '_SpecialForm'