We released luasandbox 3.0.0 last week, it would be good to get an updated package on Wikimedia wikis. It includes bugfixes for T184156, T186240, and T186091.
I just uploaded a backport of php-luasandbox to stretch-backports as well.
3.0.1 just fixes tests on 32-bit systems, but it's probably nice to package the latest version.