feat: remove existing pipedata file if there are any

Author: GuillaumeLagrange

src/run/runner/wall_time/perf/mod.rs

@@ -90,6 +90,12 @@ impl PerfRunner {
         bench_cmd: &str,
         config: &Config,
     ) -> anyhow::Result<ExitStatus> {
+        if Path::new(PERF_DATA_PATH).exists() {
+            std::fs::rename(PERF_DATA_PATH, format!("{PERF_DATA_PATH}.old")).with_context(
+                || format!("Failed to move existing perf data file at {PERF_DATA_PATH}",),
+            )?;
+        }
+
         let perf_fifo = PerfFifo::new()?;
         let runner_fifo = RunnerFifo::new()?;