Greetings,
Regarding your query, I would like to mention that while I am not an expert or an employee of NXP, I have successfully compiled and executed a Rust program on an IMX8MP device. As per my understanding, the only version of Rust supported on Kirkstone release of The Yocto Project is 1.59. Although there is a variable RUSTVERSION in poky/meta/conf/distro/include/tcmode-default.inc, there is no recipe available in poky/meta/recipes-devtool/rust for versions other than 1.59. The master layer of poky, however, supports Rust version 1.67. Since seems you are using Kirkstone, I believe you have a few options to consider:
Attempt to use the poky master branch, although this may potentially break the build for other recipes in other layers.
Endeavor to port the necessary Rust files from the master to your Kirkstone branch.
Utilize the meta-rust layer. However, please keep in mind that there is already Rust support in the poky/openembedded core layer, and there may be conflicts that arise. To address this, you will need to set layer priorities.
Opt to use Rust 1.59, if feasible. From my understanding, the changes in Rust between versions 1.59 and 1.67 should not cause significant issues.
Also, about the error in you rust-llvm compilation. Can you show your log file output in tmp/work of your build?
Best regards,