build: fix a Mac build issue
ref tikv/tikv#10867, ref tikv/tikv#11873
@@ -6,6 +6,7 @@ mod stub {
use crate::IOType;
use std::cell::Cell;
+ use strum::EnumCount;
pub fn init() -> Result<(), String> {
Err("No I/O tracing tool available".to_owned())
