Seems like something strange is going on in Scribuntos console.
Do the following
```
$ mkdir ~/mw
$ cd ~/mw
$ git clone --recursive https://gerrit.wikimedia.org/r/mediawiki/vagrant .
$ ./setup.sh
$ vagrant roles enable scribunto
$ vagrant up
```
(I also double checked with `vagrant roles enable scribunto --provision` and doing a `vagrant up` before enabling the role, and also running an explicit `vagrant provision`.)
then make a module
```
local p = {}
function p.foo()
return 'Hello'
end
return p
```
then run the following in the console
```
=p.foo()
```
and then you get something like
```
[76697ec96061ac9843807468] Exception caught: The luasandbox extension is not present, this engine cannot be used.
```
Checked whether php-luasandbox is installed and it is.
The box is a debian/contrib-stretch64.
Perhaps I do something wrong, but this has worked quite well before.