May be a duplicate of https://github.com/localstack/localstack/issues/988 but due to the age I will re raise.

I'm having issues when I throw an exception in a lambda - it isn't appearing on my dead letter queue. Is there something I am missing, I would like an sqs event exception to appear on the poison queue when an exception happens.

Below is the basic config:
 ````
    sqsclient.create_queue(QueueName = 'test-queue')
    sqsclient.create_queue(QueueName = 'test-queue-poison')

    lambda_client.create_function(
            FunctionName='MyFunction',
            Runtime='dotnetcore2.1',
            Role='role',
            Handler='Handler',
            Code=code,
	    DeadLetterConfig={'TargetArn': 'test-queue-poison-arn'})

     lambda_client.create_event_source_mapping(
		EventSourceArn='test-queue-arn',
		FunctionName='MyFunction',
		Enabled=True,
		BatchSize=100,
		StartingPosition='LATEST')
````

So when I raise a new (.net)exception within the lambda function no message is going to the dead letter queue. I can confirm that all is attached together OK as all other scenarios work, and the above code is pseudo-ish.
LAMBDA_RUNTIME_NODEJS810, LAMBDA_RUNTIME_CUSTOM_RUNTIME
)
THIS_FOLDER = os.path.dirname(os.path.realpath(__file__))
TEST_LAMBDA_PYTHON = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_integration.py')
TEST_LAMBDA_PYTHON3 = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_python3.py')
TEST_LAMBDA_NODEJS = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_integration.js')
TEST_LAMBDA_RUBY = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_integration.rb')
TEST_LAMBDA_DOTNETCORE2 = os.path.join(THIS_FOLDER, 'lambdas', 'dotnetcore2', 'dotnetcore2.zip')
TEST_LAMBDA_CUSTOM_RUNTIME = os.path.join(THIS_FOLDER, 'lambdas', 'custom-runtime')
TEST_LAMBDA_JAVA = os.path.join(LOCALSTACK_ROOT_FOLDER, 'localstack', 'infra', 'localstack-utils-tests.jar')
TEST_LAMBDA_JAVA_WITH_LIB = os.path.join(THIS_FOLDER, 'lambdas', 'java', 'lambda-function-with-lib-0.0.1.jar')
TEST_LAMBDA_ENV = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_environment.py')
TEST_LAMBDA_NAME_PY = 'test_lambda_py'
TEST_LAMBDA_NAME_PY3 = 'test_lambda_py3'
TEST_LAMBDA_NAME_JS = 'test_lambda_js'
TEST_LAMBDA_NAME_RUBY = 'test_lambda_ruby'
TEST_LAMBDA_NAME_DOTNETCORE2 = 'test_lambda_dotnetcore2'
TEST_LAMBDA_NAME_CUSTOM_RUNTIME = 'test_lambda_custom_runtime'
TEST_LAMBDA_NAME_JAVA = 'test_lambda_java'
TEST_LAMBDA_NAME_JAVA_STREAM = 'test_lambda_java_stream'
TEST_LAMBDA_NAME_JAVA_SERIALIZABLE = 'test_lambda_java_serializable'
TEST_LAMBDA_NAME_ENV = 'test_lambda_env'
MAVEN_BASE_URL = 'https://repo.maven.apache.org/maven2'
TEST_LAMBDA_JAR_URL = ('{url}/cloud/localstack/{name}/{version}/{name}-{version}-tests.jar').format(
    version=LOCALSTACK_MAVEN_VERSION, url=MAVEN_BASE_URL, name='localstack-utils')
TEST_LAMBDA_LIBS = ['localstack', 'localstack_client', 'requests',
    'psutil', 'urllib3', 'chardet', 'certifi', 'idna', 'pip', 'dns']
class LambdaTestBase(unittest.TestCase):
    def check_lambda_logs(self, func_name, expected_lines=[]):
        logs_client = aws_stack.connect_to_service('logs')