Fixed

Author: jamesgober

CHANGELOG.md

@@ -13,6 +13,7 @@
 ### Fixed
 - Disabled-path `benchmark!` macro parse error under `collector`-only builds (no `benchmark`): corrected macro expansion to use `$($body)*` in disabled arms.
 - Clippy warnings in `src/trace.rs` (`inline_always`, `uninlined_format_args`): replaced with `#[inline]` and inline format args.
+- Perf CI: baseline comparison script now supports both Criterion layouts (`target/criterion/<bench_name>/...` and flat `target/criterion/...`); fixes "criterion group directory not found" error in `.github/workflows/perf.yml`.
 
 ### Maintenance
 - Bench workflow `.github/workflows/bench.yml`: use `examples/zero_overhead.rs` for the no-default-features run, and keep `overhead_compare` for the enabled run to avoid feature gating conflicts.

scripts/compare_criterion_baseline.sh

@@ -24,12 +24,21 @@ if [[ ! -f "${BASELINE_JSON}" ]]; then
   exit 2
 fi
 
-BASE_DIR="target/criterion/${GROUP_NAME}"
-if [[ ! -d "${BASE_DIR}" ]]; then
-  echo "error: criterion group directory not found: ${BASE_DIR}" >&2
+# Determine base directory: support both nested and flat criterion layouts
+# 1) Nested:   target/criterion/<GROUP_NAME>/<KEY>/new/estimates.json
+# 2) Flat:     target/criterion/<KEY>/new/estimates.json
+if [[ -d "target/criterion/${GROUP_NAME}" ]]; then
+  BASE_DIR="target/criterion/${GROUP_NAME}"
+elif [[ -d "target/criterion" ]]; then
+  BASE_DIR="target/criterion"
+else
+  echo "error: criterion directory not found: target/criterion" >&2
   exit 2
 fi
 
+# Optional: show which layout is used (useful in CI logs)
+echo "Using Criterion base directory: ${BASE_DIR}" >&2
+
 fail_count=0
 
 # Iterate baseline entries: key, median_s, tolerance