The issue appears to be related to how QEMU emulates SVE (Scalable Vector Extension) instructions for ARM64 when running certain optimized string functions like `strnlen` and `strrchr`. The problem manifests in runtime behavior where incorrect lengths are returned, but only under specific emulation conditions. This suggests a potential bug in the emulation layer rather than the underlying instruction set or system calls.

The fact that the test passes with `sve-max-vq=2` indicates that the vector length configuration affects the outcome, pointing towards an issue within QEMU's handling of SVE instructions during runtime execution.

Therefore, this is best classified as a **runtime** error, as it relates to how QEMU executes and emulates code at runtime rather than being an issue with specific instructions or system calls themselves.

runtime