Newton user guide for openstack newton mentions the command show for a stack. Example: openstack stack show <stack_name>.
However, latest docs stein don't mention anything about this command. How can I show stack info in latest openstack/openstackclient release (stein at the moment of writing this question)?
That same functionality is still there. Check out https://docs.openstack.org/python-heatclient/stein/cli/stack.html
If the command is missing in your environment, then you probably just need to install python-heatclient. It is not available by default with the unified openstack client.