Fix crash rollback and exit semantics

scripts/run_task.py

@@ -49,6 +49,33 @@ def _emit_record(repo_root: Path, task_id: str, results_file: str, status: str,
     return 0
 
 
+def _finalize_outcome(
+    *,
+    repo_root: Path,
+    task_id: str,
+    results_file: str,
+    artifact_manager: ArtifactManager,
+    snapshot,
+    status: str,
+    reason: str,
+    candidate_score: float | None,
+) -> int:
+    diff_summary = artifact_manager.diff_summary(snapshot)
+    if status in {"discard", "crash"}:
+        artifact_manager.restore(snapshot)
+    exit_code = 1 if status == "crash" else 0
+    _emit_record(
+        repo_root=repo_root,
+        task_id=task_id,
+        results_file=results_file,
+        status=status,
+        reason=reason,
+        candidate_score=candidate_score,
+        diff_summary=diff_summary,
+    )
+    return exit_code
+
+
 def main() -> int:
     args = parse_args()
     repo_root = ROOT_DIR.resolve()
@@ -64,14 +91,15 @@ def main() -> int:
         task.runner.timeout_seconds,
     )
     if run_result.exit_code != 0:
-        return _emit_record(
+        return _finalize_outcome(
             repo_root=repo_root,
             task_id=task.id,
             results_file=task.logging.results_file,
+            artifact_manager=artifact_manager,
+            snapshot=snapshot,
             status="crash",
             reason=f"command failed with exit code {run_result.exit_code}",
             candidate_score=None,
-            diff_summary=artifact_manager.diff_summary(snapshot),
         )
 
     scorer_result = run_command(
@@ -80,14 +108,15 @@ def main() -> int:
         task.runner.timeout_seconds,
     )
     if scorer_result.exit_code != 0:
-        return _emit_record(
+        return _finalize_outcome(
             repo_root=repo_root,
             task_id=task.id,
             results_file=task.logging.results_file,
+            artifact_manager=artifact_manager,
+            snapshot=snapshot,
             status="crash",
             reason=f"scorer failed with exit code {scorer_result.exit_code}",
             candidate_score=None,
-            diff_summary=artifact_manager.diff_summary(snapshot),
         )
 
     try:
@@ -97,14 +126,15 @@ def main() -> int:
             metrics_field=task.scorer.parse.metrics_field,
         )
     except (KeyError, TypeError, ValueError) as exc:
-        return _emit_record(
+        return _finalize_outcome(
             repo_root=repo_root,
             task_id=task.id,
             results_file=task.logging.results_file,
+            artifact_manager=artifact_manager,
+            snapshot=snapshot,
             status="crash",
             reason=f"score parse failed: {exc}",
             candidate_score=None,
-            diff_summary=artifact_manager.diff_summary(snapshot),
         )
 
     decision = decide_candidate(
@@ -116,14 +146,15 @@ def main() -> int:
         run_result=run_result,
     )
 
-    return _emit_record(
+    return _finalize_outcome(
         repo_root=repo_root,
         task_id=task.id,
         results_file=task.logging.results_file,
+        artifact_manager=artifact_manager,
+        snapshot=snapshot,
         status=decision.status,
         reason=decision.reason,
         candidate_score=decision.candidate_score,
-        diff_summary=artifact_manager.diff_summary(snapshot),
     )
 
 

tests/test_execution_pipeline.py

@@ -137,7 +137,85 @@ class RunTaskCliTest(unittest.TestCase):
             self.assertEqual(record["task_id"], "skill-quality")
             self.assertEqual(record["status"], "keep")
 
-    def test_run_task_cli_records_scorer_failure(self) -> None:
+    def test_run_task_cli_restores_artifacts_after_crash(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            temp_root = Path(tmp)
+            self._copy_repo_layout(temp_root)
+
+            task_dir = temp_root / "tasks" / "runner-crash-restores"
+            fixture_dir = task_dir / "fixtures"
+            fixture_dir.mkdir(parents=True)
+            artifact_path = fixture_dir / "SKILL.md"
+            artifact_path.write_text("# Original\n", encoding="utf-8")
+            (task_dir / "task.yaml").write_text(
+                "\n".join(
+                    [
+                        "id: runner-crash-restores",
+                        "description: Runner crash restore fixture.",
+                        "artifacts:",
+                        "  include:",
+                        "    - fixtures/SKILL.md",
+                        "  exclude: []",
+                        "  max_files_per_iteration: 1",
+                        "mutation:",
+                        "  mode: direct_edit",
+                        "  allowed_file_types:",
+                        "    - .md",
+                        "  max_changed_lines: 20",
+                        "runner:",
+                        "  command: python -c \"from pathlib import Path; Path('fixtures/SKILL.md').write_text('# Mutated\\n', encoding='utf-8'); raise SystemExit(9)\"",
+                        "  cwd: tasks/runner-crash-restores",
+                        "  timeout_seconds: 30",
+                        "scorer:",
+                        "  type: command",
+                        "  command: python -c \"print('unused scorer')\"",
+                        "  parse:",
+                        "    format: json",
+                        "    score_field: score",
+                        "    metrics_field: metrics",
+                        "objective:",
+                        "  primary_metric: score",
+                        "  direction: maximize",
+                        "constraints: []",
+                        "policy:",
+                        "  keep_if: better_primary",
+                        "  tie_breakers: []",
+                        "  on_failure: discard",
+                        "budget:",
+                        "  max_iterations: 1",
+                        "  max_failures: 1",
+                        "logging:",
+                        "  results_file: work/results.jsonl",
+                        "  candidate_dir: work/candidates",
+                        "",
+                    ]
+                ),
+                encoding="utf-8",
+            )
+
+            completed = subprocess.run(
+                ["uv", "run", "python", "scripts/run_task.py", "--task", "tasks/runner-crash-restores/task.yaml"],
+                cwd=str(temp_root),
+                capture_output=True,
+                text=True,
+                encoding="utf-8",
+                check=False,
+            )
+
+            self.assertNotEqual(completed.returncode, 0, msg=completed.stderr)
+            self.assertEqual(artifact_path.read_text(encoding="utf-8"), "# Original\n")
+            results_path = temp_root / "work" / "results.jsonl"
+            self.assertTrue(results_path.exists())
+            lines = results_path.read_text(encoding="utf-8").splitlines()
+            self.assertEqual(len(lines), 1)
+            record = json.loads(lines[0])
+            self.assertEqual(record["task_id"], "runner-crash-restores")
+            self.assertEqual(record["status"], "crash")
+            self.assertEqual(record["reason"], "command failed with exit code 9")
+            self.assertIn("# Original", record["diff_summary"])
+            self.assertIn("# Mutated", record["diff_summary"])
+
+    def test_run_task_cli_returns_nonzero_on_crash_and_writes_record(self) -> None:
         with tempfile.TemporaryDirectory() as tmp:
             temp_root = Path(tmp)
             self._copy_repo_layout(temp_root)
@@ -201,7 +279,7 @@ class RunTaskCliTest(unittest.TestCase):
                 check=False,
             )
 
-            self.assertEqual(completed.returncode, 0, msg=completed.stderr)
+            self.assertNotEqual(completed.returncode, 0, msg=completed.stderr)
             results_path = temp_root / "work" / "results.jsonl"
             self.assertTrue(results_path.exists())
             lines = results_path.read_text(encoding="utf-8").splitlines()
@@ -276,7 +354,7 @@ class RunTaskCliTest(unittest.TestCase):
                 check=False,
             )
 
-            self.assertEqual(completed.returncode, 0, msg=completed.stderr)
+            self.assertNotEqual(completed.returncode, 0, msg=completed.stderr)
             results_path = temp_root / "work" / "results.jsonl"
             self.assertTrue(results_path.exists())
             lines = results_path.read_text(encoding="utf-8").splitlines()