当我开始使用 localstack 制作基础设施时，我得到了这个
Starting local dev environment. CTRL-C to quit.
cannot import name 'dns_server' from 'localstack_ext.services' (unknown location)
Starting mock S3 (http port 4572)...
Starting mock SNS (http port 4575)...
2019-09-21T13:11:08:INFO:localstack.multiserver: Starting multi API server process on port
51492
Starting mock SQS (http port 4576)...
Starting mock DynamoDB (http port 4569)...
Starting mock Lambda service (http port 4574)...
Starting mock CloudWatch Logs (http port 4586)...
Ready.
但是当我执行http://localhost:4569时，它会抛出错误并且没有显示它已启动。以下是我得到的错误
2019-09-21T13:15:05:ERROR:localstack.services.generic_proxy: Error forwarding request: the
JSON object must be str, bytes or bytearray, not NoneType Traceback (most recent call last):
File "/Users//workspaces/others/localstack/localstack/services/generic_proxy.py", line 240,
in forward
path=path, data=data, headers=forward_headers)
File"/Users//workspaces/others/localstack/localstack/services/dynamodb/dynamodb_listener.py",
line 35, in forward_request
data = json.loads(to_str(data))
File"/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/init.py", line 341, in loads
raise TypeError(f'the JSON object must be str, bytes or bytearray, '
TypeError: the JSON object must be str, bytes or bytearray, not NoneType
错误2：
2019-09-21T13:14:11:ERROR:localstack.services.generic_proxy: Error forwarding request:'QueueUrl' Traceback (most recent call last):
File "/Users//workspaces/others/localstack/localstack/services/generic_proxy.py", line 240, in forward
path=path, data=data, headers=forward_headers)
File "/Users//workspaces/others/localstack/localstack/services/sqs/sqs_listener.py", line 53, in forward_request
self._set_queue_attributes(req_data)
File "/Users/*****/workspaces/others/localstack/localstack/services/sqs/sqs_listener.py", line 245, in _set_queue_attributes
queue_url = req_data['QueueUrl'][0]
KeyError: 'QueueUrl'`
请对此提供帮助，这对我来说是一个障碍。