"bash: cannot set terminal process group (-1): Inappropriate ioctl for device" printed at the start of sagemaker jobs

[abhinavs95]

The entrypoint script for the containers is executed with monitor mode enabled (using -m flag), eg. here https://github.com/aws/sagemaker-pytorch-container/blob/97e611b4cb2df13d966d508e56d1c990439b2163/docker/1.3.1/py3/Dockerfile.gpu#L166

This prints the following message at the start of any sagemaker job that uses the container:

bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell

Removing the -m flag gets rid of this message. Is there a particular reason for using this flag? If not we should remove it from all Dockerfiles.