I want to rewind discussion a little bit and talk about one of original
assumptions:

> 2) networking is not in scope. Distributed builds are considered an
extension
> of the local system, so they don't count as networking. Distributed build
> tools need to emulate the file system of the originator.

I don't think this is correct. Distributed builds do exist so there may
be file system change between systems. I think we need to clarify the
use case.