It won't work in those cases. Do you have explicit examples? I suspect this won't come up much as Rust has, IME, much broader target support. (Including platforms without a GPOS)
They’re plugging away at it. A major milestone was getting unwinding to work. I’d say they’re getting quite close and it’s getting better and better. It’s usable for Linux kernel compilation I believe which unlocks Rust to be used for the non-driver components in the kernel.
...Since the Gentoo Portage package manager indirectly depends on cryptography, ""we will probably have to entirely drop support for architectures that are not supported by Rust"". He listed five architectures that are not supported by upstream Rust (alpha, hppa, ia64, m68k, and s390) and an additional five that are supported but do not have Gentoo Rust packages (mips, 32-bit ppc, sparc, s390x, and riscv).
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