tests/vm/build-image.sh writes site-vars.yml with pxe_nic_mac (isolated network NIC) and corp_nic_mac (NAT NIC) and passes it to build-usb.sh.
tests/vm/build-image.sh writes site-vars.yml with pxe_nic_mac (isolated network NIC) and corp_nic_mac (NAT NIC) and passes it to build-usb.sh.