I've built .exes for Windows just fine on Linux. I don't know about Apple stuff, though, I don't think there's any built-in Linux tooling to submit an executable for Apple's signature scheme.

Can’t you just replace the “cargo” command with “cross”

    cross build —-target=…

https://github.com/cross-rs/cross

Cross-building for Apple is possible, but it's far from smooth with many steps that you have to figure out by yourself unfortunately.

I use this which seems to work well for my projects. Particularly their docker image.

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