cross VS cargo-zigbuild

To compile a program with musl on a glibc system you can use cross-rs!

I cross compile to Mac, bsd, windows, etc cross ... Works great for me with either docker or podman.

If docker is available for you, https://github.com/cross-rs/cross is another and reliable way to solve this kind of problem. I do use it regularly.

We are using https://github.com/cross-rs/cross.

There is some built-in support in rustc for cross-compiling, but getting the build to actually work can be tricky due to the need for an appropriate linker. Instead, we’re going to use the Cross crate, which used to be maintained by the Rust Embedded Working Group Tools group.

I have used cross before to cross compile from Linux to other Linux. It has a section on it's wiki about this. Maybe that could be of help.

You can use cross to build your application and copy the artifacts into an alpine armv7 container. It would also build faster due to using cross compilation rather than QEMU.

Looks like cross is the easiest way to get something cross-compiled but its Mac support is blocked behind building your own build image. Even that repo says that it might be broken.

Bonus: if you’re working with Rust and doing a lot of cross platform stuff, check out cross. It runs QEMU in docker so you can run tests on a bunch of different emulated targets easily- literally a one line setup, it’s kind of magical.

It's also not as naturally cross-compilable as Go, though that's partly a side-effect of not accepting being a semi-closed ecosystem to achieve that and cross exists as a stop-gap while things like cargo-zigbuild explore less drastic options.

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