The problem with macros in Rust is that they have full access to your computer. This is literally an invitation for exploitation. I think we will see the attacks based on this vulnerability once Rust becomes more popular.
I do share the sentiment - and complain about this frequently - but any environment with build scripts can wreck your computer. Encrypt what you can, I guess, but software engineering is an extremely dangerous job wrt security.
I think using something like the pledge syscall from OpenBSD in the compiler could be useful. That way, it's controlled at the process level which things can be accessed on the system.
But thank you for letting me learn something useful.
But go off, king.