I've been getting intermittent failures on Xcode code compiling my app on multiple platforms because it fails to compile a metal shader.
The Metal Toolchain was not installed and could not compile the Metal source files. Download the Metal Toolchain from Xcode > Settings > Components and try again.
Sometimes if I re-run it, it works fine. Then I'll run it again, and it will fail.
If you tell me to file a feedback, please tell me what information would be useful and actionable, because this is all I have.