Luasandbox gives a sigsegv on at least amd64 but the devs refuses to accept it. After testing on several OS and versions of the OSes, both in host and client, I am pretty sure it is consistent. I have not tested on other archs, but feel free to do so.
If you must do extensive testing, then try to avoid the luasandbox, use the standalone solution.
Having several competing systems that all messes with the stack is not very safe. I wrote a pretty long report where and how it sigsegv, but when devs started to demand I should provide "proof", I got feed up and deleted it.
Someone else should do the investigation, perhaps the dev will belive them. In the mean time hope that someone find the bug and fix it, before someone find a way to exploit it.
Code throwing a sigsegv from activity on the stack is a pretty good indication of a serious malfunction, but hopefully not something that can be exploited. (Can always hope…)
Yes, I have reported the bug, and yes I have warned about this.
For what it is worth; I'm not using luasandbox myself, as I suspect this is not only an annoying bug, but a security issue. (The code manipulates the stack and gives a sigsegv, so yes, it is most likely a security issue.)