cargo-zigbuild VS rust.aws-cdk-lambda

https://github.com/rust-cross/cargo-zigbuild

I’m curious what the blockers are for rustc to cross-compile like zig does natively.

Perhaps you can try cargo-zigbuild, it uses zig-cc for cross-compilation instead of creating a container, so it should be much more lightweight on MacOS, without all the cost of virtualization and file sharing.

I have tried, however I haven't been able to get it to work reliably (e.g. building on windows + linux on WSL works, Mac is a lot more involved; tried building for windows + linux on Mac and I couldn't get it to work at all); I've had some luck using zigbuild but that too doesn't seem to work for Mac.

Zig also takes this approach, and even exposes its C compiler (which if I recall correctly is basically Clang plus diverse sysroots and other customisation out of the box) as a separate `zig cc`.

I do a lot of work in Rust, and cross-compilation can be a pain when you have a lot of C dependencies. Fortunately https://github.com/messense/cargo-zigbuild exists. It sounds crazy, but using Zig's inbuilt C compiler to help build my Rust projects has been the smoothest option I've found.

I can't help but wonder if it would be worth it for Rust to follow D and Zig by shipping its own inbuilt C compiler, even if they still want to also support external C toolchains. It should be roughly the same effort as it was for Zig, given that they both use LLVM.

Wait until you start using cargo zig-build. Suddenly it becomes way better than Go's cross compiler because you can seamlessly cross-compile rust AND C (thanks to Zig compiler of course). https://github.com/messense/cargo-zigbuild

Also check out https://github.com/rnag/rust.aws-cdk-lambda, which is a CDK-based solution for this.

Examples of sample CDK apps I've been able to test can be found here.