Firefox build dependencies.

[KPECT]

Hello guys.

I have this option set in my portmaster.rc config:

# Install packages for build-only dependencies (--packages-build)
PM_PACKAGES_BUILD=pmp_build

However, when Firefox is being built from ports it also builds rust and llvm as dependencies first, which takes a lot of time.
Is it possible to fetch those build dependencies as binaries from package repository?
Best regards,
Sergey.