fix(benchmark-report): drop task cost fallback

modules/local/aggregate_benchmark_report_data/bin/benchmark_report_aggregate.py

@@ -62,13 +62,13 @@ def _lookup_cost(
     return None
 
 
-def _cost_or_task(cost_row: dict[str, Any] | None, key: str, task_cost: float, default: float = 0.0) -> float:
+def _cost_or_task(cost_row: dict[str, Any] | None, key: str, default: float = 0.0) -> float:
     if not cost_row:
-        return task_cost if key in {"cost", "used_cost"} else default
+        return default
 
     value = cost_row.get(key)
     if value is None:
-        return task_cost if key in {"cost", "used_cost"} else default
+        return default
 
     return float(value)
 
@@ -311,21 +311,17 @@ def build_report_data(jsonl_dir: Path, include_failed_runs: bool = False) -> dic
             }
 
         cost_row = _lookup_cost(costs_index, run_id=run_id, process=process, process_short=process_short, hash_short=hash_short)
-        task_cost = float(t.get("cost") or 0.0)
 
         if cost_row:
-            run_cost_acc[run_group_key]["cost"] += _cost_or_task(cost_row, "cost", task_cost)
-            run_cost_acc[run_group_key]["used_cost"] += _cost_or_task(cost_row, "used_cost", task_cost)
-            run_cost_acc[run_group_key]["unused_cost"] += _cost_or_task(cost_row, "unused_cost", task_cost, default=0.0)
-        else:
-            run_cost_acc[run_group_key]["cost"] += task_cost
-            run_cost_acc[run_group_key]["used_cost"] += task_cost
+            run_cost_acc[run_group_key]["cost"] += _cost_or_task(cost_row, "cost")
+            run_cost_acc[run_group_key]["used_cost"] += _cost_or_task(cost_row, "used_cost")
+            run_cost_acc[run_group_key]["unused_cost"] += _cost_or_task(cost_row, "unused_cost")
 
         if has_cost_rows:
             overview_key = (group, process_short)
-            cost_group_acc[overview_key]["total_cost"] += _cost_or_task(cost_row, "cost", task_cost)
-            cost_group_acc[overview_key]["used_cost"] += _cost_or_task(cost_row, "used_cost", task_cost)
-            cost_group_acc[overview_key]["unused_cost"] += _cost_or_task(cost_row, "unused_cost", task_cost, default=0.0)
+            cost_group_acc[overview_key]["total_cost"] += _cost_or_task(cost_row, "cost")
+            cost_group_acc[overview_key]["used_cost"] += _cost_or_task(cost_row, "used_cost")
+            cost_group_acc[overview_key]["unused_cost"] += _cost_or_task(cost_row, "unused_cost")
             cost_group_acc[overview_key]["n_tasks"] += 1
 
         status = t.get("status")

modules/local/aggregate_benchmark_report_data/tests/test_aggregate.py

@@ -31,14 +31,14 @@ def test_build_report_data_has_all_sections(tmp_path, make_run, flat_task, write
     }
 
 
-def test_run_costs_without_cur_uses_task_cost(tmp_path, make_run, flat_task, write_run_json):
+def test_run_costs_without_cur_are_zero(tmp_path, make_run, flat_task, write_run_json):
     data_dir = tmp_path / "data"
     jsonl_dir = tmp_path / "jsonl_bundle"
     write_run_json(data_dir, [make_run(tasks=[flat_task(cost=4.2)])])
     normalize_jsonl(data_dir, jsonl_dir)
 
     data = build_report_data(jsonl_dir)
-    assert data["run_costs"][0]["cost"] == 4.2
+    assert data["run_costs"][0]["cost"] == 0.0
     assert data["run_costs"][0]["used_cost"] is None
 
 

modules/local/normalize_benchmark_jsonl/bin/benchmark_report_normalize.py

@@ -179,7 +179,7 @@ def extract_tasks(runs: list[dict[str, Any]]) -> list[dict[str, Any]]:
                     "peak_rss": task.get("peakRss", 0),
                     "read_bytes": task.get("readBytes", 0),
                     "write_bytes": task.get("writeBytes", 0),
-                    "cost": task.get("cost"),
+                    "cost": None,
                     "executor": task.get("executor", ""),
                     "machine_type": task.get("machineType", ""),
                     "cloud_zone": task.get("cloudZone", ""),

modules/local/normalize_benchmark_jsonl/tests/test_normalize.py

@@ -24,7 +24,7 @@ def test_cached_count_extracted(make_run, flat_task):
 def test_nested_tasks_unwrapped(make_run, nested_task):
     run = make_run(tasks=[nested_task(cost=2.0), nested_task(cost=3.0)])
     rows = extract_tasks([run])
-    assert sum(r["cost"] for r in rows) == 5.0
+    assert all(r["cost"] is None for r in rows)
 
 
 def test_failed_tasks_filtered(make_run, flat_task):