Hello Genodeans
We have recognized that acpica-tools that are newer than March 16. 2016 cause problem when building virtualbox5.
This is due to the commit https://github.com/acpica/acpica/commit/f9a88a4c1cd020b6a5475d63b29626852a0b...
So be careful, when your distribution wants to update this package (we have encountered this on Debian testing, Debian unstable and ARCH so far).
Best regards Pirmin