Creating a Mac/Linux multiplatform Swift package wrapping a static C library

I'm attempting to create a Swift package that wraps the librclone library, but includes binary files for both Linux and Mac, in both arm64 and amd64 architectures. (Might include iOS at a later date.)

I'm able to build all the artifacts (.a and .h files for each platform). I'm having trouble building cross-platform, so I have to build each manually on it's own OS/architecture, but that's a Go issue and not relevant here.

But I'm having trouble figuring out how to package them all together with SPM and wondering if it's not really possible.

I know that if I was just targeting Apple platforms I could build an xcframework file.

I also found that if you want to deliver a Mac/Linux binary, you can instead use an Artifact Bundle. But as far as I can find it doesn't support libraries, only executables.

Anything I'm missing or overlooking?