Hi Gordon,
We are able to run our unit tests with our current DEV build for WooCommerce 3.X now (unreleased, coming out today or tomorrow) but we just noticed you’re running PHP 7.0.16… We’re suspecting this may be related to that PHP version. We’re working on building and testing a VM today with PHP 7.0.X and see if we can reproduce your exact error that way.
Next update later today or tomorrow.
Thanks,
– Sean