SyntaxError: future feature annotations is not defined

I am running detectron2 in a docker file (clone from repository) and while running the demo.py I am getting the following error:

Traceback (most recent call last):
File "demo.py", line 17, in
from predictor import VisualizationDemo
File "/home/appuser/detectron2_repo/demo/predictor.py", line 10, in
from detectron2.engine.defaults import DefaultPredictor
File "/home/appuser/.local/lib/python3.6/site-packages/detectron2/engine/__init__.py", line 12, in
from .defaults import *
File "/home/appuser/.local/lib/python3.6/site-packages/detectron2/engine/defaults.py", line 38, in
from detectron2.modeling import build_model
File "/home/appuser/.local/lib/python3.6/site-packages/detectron2/modeling/__init__.py", line 5, in
from .backbone import (
File "/home/appuser/.local/lib/python3.6/site-packages/detectron2/modeling/backbone/__init__.py", line 15, in
from .vit import ViT, SimpleFeaturePyramid, get_vit_lr_decay_rate
File "/home/appuser/.local/lib/python3.6/site-packages/detectron2/modeling/backbone/vit.py", line 10, in
from fairscale.nn.checkpoint import checkpoint_wrapper
File "/home/appuser/.local/lib/python3.6/site-packages/fairscale/__init__.py", line 12, in
from . import nn
File "/home/appuser/.local/lib/python3.6/site-packages/fairscale/nn/__init__.py", line 9, in
from .data_parallel import FullyShardedDataParallel, ShardedDataParallel
File "/home/appuser/.local/lib/python3.6/site-packages/fairscale/nn/data_parallel/__init__.py", line 8, in
from .fully_sharded_data_parallel import FullyShardedDataParallel, OffloadConfig, TrainingState, auto_wrap_bn
File "/home/appuser/.local/lib/python3.6/site-packages/fairscale/nn/data_parallel/fully_sharded_data_parallel.py", line 43, in
from fairscale.nn.misc import FlattenParamsWrapper
File "/home/appuser/.local/lib/python3.6/site-packages/fairscale/nn/misc/__init__.py", line 12, in
from .flatten_params_wrapper import FlattenParamsWrapper
File "/home/appuser/.local/lib/python3.6/site-packages/fairscale/nn/misc/flatten_params_wrapper.py", line 34, in
from fairscale.experimental.nn.ssd_offload import SsdFlatParameter
File "/home/appuser/.local/lib/python3.6/site-packages/fairscale/experimental/nn/ssd_offload.py", line 6
from __future__ import annotations
^
SyntaxError: future feature annotations is not defined

Should I upgrade python to 3.7 as currently it is running in 3.6.9 to fix this issue or any other fix?

Start with demo.py and demo/predictor.py, then inspect the import chain ending at fairscale/experimental/nn/ssd_offload.py. Reproduce the failure under Python 3.6.9 and check the project's supported Python versions and dependency requirements; done means the demo starts without this syntax error or the compatibility limitation is documented.

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