sagemaker-inference-toolkit: Error in batch transform with custom image

Describe the problem

I needed to add GluonCV library in my code environment, and since the Default MXNet container does not have the python package, I needed to create a custom image with the python package installed.

I got the default MXNet container from here: https://github.com/aws/sagemaker-mxnet-serving-container and follow all the instructions. To include GluonCV, i then simply added this to the docker file and build the image

RUN ${PIP} install --no-cache-dir mxnet-mkl==$MX_VERSION \
                                  mxnet-model-server==$MMS_VERSION \
                                  keras-mxnet==2.2.4.1 \
                                  numpy==1.14.5 \
				  gluoncv \
                                  onnx==1.4.1 \
                                  ...

I build the image, then uploaded it to a AWS ECR.

I am able to verify that the docker image has been successfully uploaded and I have a valid URI like so: 552xxxxxxx.dkr.ecr.us-west-2.amazonaws.com/preprod-mxnet-serving:1.4.1-cpu-py3

THEN, when instantiating the MXNet model, I added a reference to this image URI like so

sagemaker_model = MXNetModel(model_data = 's3://' + sagemaker_session.default_bucket() + '/model/yolo_object_person_detector.tar.gz',
                            role = role, 
                             entry_point = 'entry_point.py',
                             image = '552xxxxxxxx.dkr.ecr.us-west-2.amazonaws.com/preprod-mxnet-serving:1.4.1-cpu-py3',
                             py_version='py3',
                             framework_version='1.4.1',
                            sagemaker_session = sagemaker_session)

BUT i got an error message: Here is the full log

Traceback (most recent call last):
File "/usr/local/bin/dockerd-entrypoint.py", line 21, in <module>
serving.main()
File "/usr/local/lib/python3.6/site-packages/sagemaker_mxnet_serving_container/serving.py", line 54, in main
_start_model_server()
File "/usr/local/lib/python3.6/site-packages/retrying.py", line 49, in wrapped_f
return Retrying(*dargs, **dkw).call(f, *args, **kw)
File "/usr/local/lib/python3.6/site-packages/retrying.py", line 206, in call
return attempt.get(self._wrap_exception)
File "/usr/local/lib/python3.6/site-packages/retrying.py", line 247, in get
six.reraise(self.value[0], self.value[1], self.value[2])
File "/usr/local/lib/python3.6/site-packages/six.py", line 693, in reraise
raise value
File "/usr/local/lib/python3.6/site-packages/retrying.py", line 200, in call
attempt = Attempt(fn(*args, **kwargs), attempt_number, False)
File "/usr/local/lib/python3.6/site-packages/sagemaker_mxnet_serving_container/serving.py", line 49, in _start_model_server
model_server.start_model_server(handler_service=HANDLER_SERVICE)
File "/usr/local/lib/python3.6/site-packages/sagemaker_inference/model_server.py", line 63, in start_model_server
'/dev/null'])
File "/usr/local/lib/python3.6/subprocess.py", line 287, in call
with Popen(*popenargs, **kwargs) as p:
File "/usr/local/lib/python3.6/subprocess.py", line 729, in __init__
restore_signals, start_new_session)
File "/usr/local/lib/python3.6/subprocess.py", line 1364, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)

OSError: [Errno 14] Bad address: 'tail'