However, there are three points which annoy me. First, the Rust compiler is huge (LLVM based). Second, it requires a native Rust compiler for bootstrap. Third, it doesn't compile to C which makes porting to other platforms difficult. Nim doesn't have these problems. It is small, self-hosting, and easily portable.

Not compiling to C is a feature. It insulates us from the undefined behavior of C (signed overflow never results in UB in Rust, for example) and allows us to actually get proper debug info.

Furthermore, if your frontend doesn't know about structure layout then you forgo some important systems language features. For example, you can't implement sizeof as a compile time constant.

Sure and you only need to call libclang for each different platform. Or is it on every platform? ;-)

(I agree that it's a tradeoff generally, I'm just not sure this example is particularly motivating.)

No, because the interface is

    int stat(const char *path, struct stat *buf);

?

(Which is how stuff like https://docs.rs/libc/0.2.16/libc/fn.stat.html is built)

I still think that, given Cargo, the one-time cost makes it worth it, but after seeing my error, think that the point makes more sense. Thank you for being patient. :)