ImportError: cannot import name _thread on MacOS

Stack Trace

Traceback (most recent call last):
File "/Users/ville.lahdenvuo/Library/Python/2.7/bin/mssh", line 17, in
from ec2instanceconnectcli import mops
File "/Users/ville.lahdenvuo/Library/Python/2.7/lib/python/site-packages/ec2instanceconnectcli/mops.py", line 17, in
from ec2instanceconnectcli.EC2InstanceConnectCLI import EC2InstanceConnectCLI
File "/Users/ville.lahdenvuo/Library/Python/2.7/lib/python/site-packages/ec2instanceconnectcli/EC2InstanceConnectCLI.py", line 19, in
import botocore.session
File "/Users/ville.lahdenvuo/Library/Python/2.7/lib/python/site-packages/botocore/session.py", line 30, in
import botocore.credentials
File "/Users/ville.lahdenvuo/Library/Python/2.7/lib/python/site-packages/botocore/credentials.py", line 26, in
from dateutil.parser import parse
File "/Users/ville.lahdenvuo/Library/Python/2.7/lib/python/site-packages/dateutil/parser/__init__.py", line 2, in
from ._parser import parse, parser, parserinfo
File "/Users/ville.lahdenvuo/Library/Python/2.7/lib/python/site-packages/dateutil/parser/_parser.py", line 50, in
from .. import tz
File "/Users/ville.lahdenvuo/Library/Python/2.7/lib/python/site-packages/dateutil/tz/__init__.py", line 2, in
from .tz import *
File "/Users/ville.lahdenvuo/Library/Python/2.7/lib/python/site-packages/dateutil/tz/tz.py", line 21, in
from six.moves import _thread
ImportError: cannot import name _thread

Same issue as: https://github.com/awslabs/aws-shell/issues/161 and same solution works.

Start with the reported mssh import path through ec2instanceconnectcli/mops.py and the failing import in dateutil/tz/tz.py. Compare the linked aws-shell issue and its referenced solution, then verify that the CLI imports successfully on macOS without the reported ImportError.

Written by the indexing model from the issue text.