Okay, then why does it fail when it should then still use llvm15? The author states this is an llvm16 issue, but unless the driver was built against llvm16, it

Okay, then why does it fail when it should then still use llvm15? The author states this is an llvm16 issue, but unless the driver was built against llvm16, it should still be loading llvm15. If it was built against llvm16 (or loads llvm16), and doesn't work, that's not a failure of anything other than QA testing.