It looks like a duplicate of old issue https://github.com/localstack/localstack/issues/78
But now it's reproducible for me with the latest version of LocalStack. 
import re
import os
import socket
import logging
import platform
import tempfile
import subprocess
from os.path import expanduser
import six
from boto3 import Session
from localstack.constants import (
    DEFAULT_SERVICE_PORTS, LOCALHOST, PATH_USER_REQUEST, DEFAULT_PORT_WEB_UI, TRUE_STRINGS, FALSE_STRINGS,
    DEFAULT_LAMBDA_CONTAINER_REGISTRY)
TRUE_VALUES = ('1', 'true')
LAMBDA_JAVA_OPTS = os.environ.get('LAMBDA_JAVA_OPTS', '').strip()
KINESIS_SHARD_LIMIT = os.environ.get('KINESIS_SHARD_LIMIT', '').strip() or '100'
KINESIS_LATENCY = os.environ.get('KINESIS_LATENCY', '').strip() or '500'
if 'DEFAULT_REGION' not in os.environ:
    os.environ['DEFAULT_REGION'] = 'us-east-1'
DEFAULT_REGION = os.environ['DEFAULT_REGION']
KINESIS_ERROR_PROBABILITY = float(os.environ.get('KINESIS_ERROR_PROBABILITY', '').strip() or 0.0)
DYNAMODB_ERROR_PROBABILITY = float(os.environ.get('DYNAMODB_ERROR_PROBABILITY', '').strip() or 0.0)
HOSTNAME = os.environ.get('HOSTNAME', '').strip() or LOCALHOST
HOSTNAME_EXTERNAL = os.environ.get('HOSTNAME_EXTERNAL', '').strip() or LOCALHOST