Unable to properly specify a linker for building to x86 Darwin from Linux

[SwissArmyWrench]

Hey folks, I am working towards my first release of a small little tool I wrote, and I am working on compiling my binaries for release. I am trying to run cross-rs on my dev server to compile binaries for MacOS. However, I am encountering a linker problem. After doing all of the rest of the compilation without issue, it fails when trying to do the linking. I get an error that says note: cc: error: unrecognized command-line option -arch.

Talking about this with one of my buddies, we believe that this is due to the compilation happening within Linux but with the rustup target for macOS: On macOS, gcc is actually an alias for the clang compiler/linker, but on the linux system, the call to gcc invokes the actuall GCC, the GNU C Compiler. To try to confirm this, I installed clang on my system and then called it with the -arch flag, and it complained about it not being used correctly, instead of the previous error that didn't recognize the option at all. This leads me to believe i'm on the right track with thinking that rustup is expecting to find a different linker that it actually gets.

Now to actually do something about it. I currently have in my Cross.toml some custom settings for the x86_64-apple-darwin target. This includes some prebuild commands that install Clang. However, I am having a difficult time getting the compilation process to actually use clang, even though it's there. I have tried things like adding a set command to set the environment variable to use the linker, using an alias, passing the env variable directly with the cross build command, but with no luck whatsoever.

Can anybody who's done this walk me through how they made it work? Thanks in advance.

[Emilgardis]

Firstly, are you actually using cross? We don't support x86_64-apple-darwin by default, you have to make the image yourself using https://github.com/cross-rs/cross-toolchains?tab=readme-ov-file#apple-targets

[Emilgardis]

There should be a warning about cross falling back to the native cargo