Rust bindings fail to build built-in backends on Darwin aarch64

[eliasboegel]

Hi,

I was just trying to build both my own application as well as the Rust examples on a new machine, running an aarch64 Darwin system. The build of the interface appears to succeed (build process shows no errors), however running with any backend (even /cpu/self/ref/* and /cpu/self/opt/*) will result in Backend not currently compiled: /cpu/self Consult the installation instructions to compile this backend.

I am currently using a standard Clang 16.0.6 toolchain, however the same issue occurs with an Apple Clang (15) distribution. Building and running the tests of the C library works without issue, so I don't see this being an issue with the make configuration. I'm currently still unsure if this is a libCEED issue with Bindgen or purely a Bindgen problem. It is also unclear if this is a Darwin problem, or an aarch64 problem as I don't currently have neither an Intel Darwin or Linux aarch64 machine available.

Have the libCEED Rust bindings previously successfully built under Darwin, especially on an aarch64 machine, or are there any ideas what the issue could be? My (unsubstantiated) suspicion is a linker issue.