Add dry run option to custom benchmark report script and update workflow to use it

.github/scripts/custom_benchmark_report.py

@@ -346,6 +346,11 @@ if __name__ == "__main__":
     parser = argparse.ArgumentParser(
         description="Load Criterion benchmark results from JSON files and generate an HTML table with links to reports."
     )
+    parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="Perform a dry run without writing the HTML file.",
+    )
     parser.add_argument(
         "--criterion-dir",
         type=str,
@@ -372,6 +377,12 @@ if __name__ == "__main__":
 
     args = parser.parse_args()
 
+    if args.dry_run:
+        print(
+            "Dry run mode: No files will be written. Use --dry-run to skip writing the HTML file."
+        )
+        sys.exit(0)
+
     criterion_path = Path(args.criterion_dir)
     output_file_path = Path(args.output_file)
 

.github/workflows/run-benchmarks.yml

@@ -33,6 +33,16 @@ jobs:
         with:
           toolchain: stable
 
+      - name: Install Python
+        uses: actions/setup-python@v4
+      - name: Install uv
+        uses: astral-sh/setup-uv@v5
+      - name: Setup venv
+        run: |
+          uv venv
+          uv pip install pandas
+          uv run .github/scripts/custom_benchmark_report.py --dry-run
+
       - name: Run benchmarks
         run: cargo bench --features bench
 
@@ -44,8 +54,7 @@ jobs:
             echo "No benchmark reports found, skipping custom report generation."
             exit 1
           fi
-          pip3 install pandas
-          python3 .github/scripts/custom_benchmark_report.py
+          uv run .github/scripts/custom_benchmark_report.py
 
       - name: Upload benchmark reports
         uses: actions/upload-artifact@v4