# - WORKING_TOPOLOGY - Path to topology yaml file of the reserved testbed.
# Functions called:
# - die - Print to stderr and exit.
+ # - ansible_hosts - Perform an action using ansible, see ansible.sh
# Traps registered:
# - EXIT - Calls cancel_all for ${WORKING_TOPOLOGY}.
# - EXIT - Failure to untrap is reported, but ignored otherwise.
# Functions called:
# - die - Print to stderr and exit.
+ # - ansible_hosts - Perform an action using ansible, see ansible.sh
set -xo pipefail
set +eu # We do not want to exit early in a "teardown" function.