So trying to build an iso with modifications based on https://docs.starlingx.io/developer_resources/build_guide.html#development-environment-setup

i seem to be running into an issue with this step

  1. cd  
$MY_REPO_ROOT_DIR/stx-tools/centos-mirror-tools && bash 
download_mirror.sh

with a message

This system is not registered with an entitlement server. You can use subscription-manager to register

Do i really need a redhat registration to build an image ?