Probably related to #1643 , but what appears to happen seems different (at least the error is).

From what I can see, the lambda executes successfully, but then fails to return the result, returning the following instead:
```json
{
    "Type": "Server",
    "message": "Error executing Lambda function arn:aws:lambda:ap-northeast-1:000000000000:function:service-stage-functionName: module 'botocore.errorfactory' has no attribute 'ResourceAlreadyExistsException' Traceback (most recent call last):\n  File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 106, in _store_logs\n    logs_client.create_log_group(logGroupName=log_group_name)\n  File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 357, in _api_call\n    return self._make_api_call(operation_name, kwargs)\n  File \"/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py\", line 661, in _make_api_call\n    raise error_class(parsed_response, operation_name)\nbotocore.errorfactory.ResourceAlreadyExistsException: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists\n\nDuring handling of the above exception, another exception occurred:\n\nTraceback (most recent call last):\n  File \"/opt/code/localstack/localstack/services/awslambda/lambda_api.py\", line 339, in run_lambda\n    event, context=context, version=version, asynchronous=asynchronous)\n  File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 81, in execute\n    return do_execute()\n  File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 70, in do_execute\n    self._store_logs(func_details, log_output, invocation_time)\n  File \"/opt/code/localstack/localstack/services/awslambda/lambda_executors.py\", line 107, in _store_logs\n    except botocore.errorfactory.ResourceAlreadyExistsException:\nAttributeError: module 'botocore.errorfactory' has no attribute 'ResourceAlreadyExistsException'\n",
    "__type": "InternalFailure"
}
```

Looking at the localstack end I see the following log:

```
...(lambda execution log, SUCCESS etc)...
> REPORT RequestId: 00e1e000-0e00-000c-0000-8ccf00ab00ba	Duration: 52.74 ms	Billed Duration: 100 ms	Memory Size: 1536 MB	Max Memory Used: 5 MB	
> nohup: failed to run command 'python': No such file or directory
2019-10-25T11:46:25:WARNING:localstack.services.awslambda.lambda_api: Error executing Lambda function arn:aws:lambda:ap-northeast-1:000000000000:function:service-stage-functionName: module 'botocore.errorfactory' has no attribute 'ResourceAlreadyExistsException' Traceback (most recent call last):
  File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 106, in _store_logs
    logs_client.create_log_group(logGroupName=log_group_name)
  File "/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py", line 357, in _api_call
    return self._make_api_call(operation_name, kwargs)
  File "/opt/code/localstack/.venv/lib/python3.6/site-packages/botocore/client.py", line 661, in _make_api_call
    raise error_class(parsed_response, operation_name)
botocore.errorfactory.ResourceAlreadyExistsException: An error occurred (ResourceAlreadyExistsException) when calling the CreateLogGroup operation: The specified log group already exists

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/code/localstack/localstack/services/awslambda/lambda_api.py", line 339, in run_lambda
    event, context=context, version=version, asynchronous=asynchronous)
  File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 81, in execute
    return do_execute()
  File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 70, in do_execute
    self._store_logs(func_details, log_output, invocation_time)
  File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 107, in _store_logs
    except botocore.errorfactory.ResourceAlreadyExistsException:
AttributeError: module 'botocore.errorfactory' has no attribute 'ResourceAlreadyExistsException'
```

Will update if I am able to create an easily reproducible case!
import re
import os
import sys
import ssl
import json
import socket
import inspect
import logging
import traceback
import click
import requests
from ssl import SSLError
from flask_cors import CORS
from requests.structures import CaseInsensitiveDict
from requests.models import Response, Request
from six import iteritems
from six.moves.socketserver import ThreadingMixIn
from six.moves.urllib.parse import urlparse
from six.moves.BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
from localstack.config import TMP_FOLDER, USE_SSL, EXTRA_CORS_ALLOWED_HEADERS, EXTRA_CORS_EXPOSE_HEADERS
from localstack.constants import ENV_INTERNAL_TEST_RUN
from localstack.utils.common import FuncThread, generate_ssl_cert, to_bytes
QUIET = False
SERVER_CERT_PEM_FILE = '%s/server.test.pem' % (TMP_FOLDER)