fix sandbox replace trace identity

test/test_sandbox_usecase.py

@@ -9,7 +9,7 @@ from adapter.observability.noop import NoopMetrics, NoopTracer
 from domain.sandbox import SandboxSession, SandboxStatus
 from repository.sandbox_lock import ProcessLocalSandboxLifecycleLocker
 from repository.sandbox_session import InMemorySandboxSessionRepository
-from usecase.interface import AttrValue, Attrs
+from usecase.interface import Attrs, AttrValue
 from usecase.sandbox import CleanupExpiredSandboxes, CreateSandbox, CreateSandboxCommand
 
 CHAT_ID = UUID('11111111-1111-1111-1111-111111111111')
@@ -486,6 +486,10 @@ def test_create_sandbox_replace_records_observability_and_final_active_count(
         'usecase.create_sandbox',
         {'chat.id': str(CHAT_ID)},
         {
+            'sandbox.previous_session.id': str(SESSION_OLD_ID),
+            'sandbox.previous_container.id': 'container-old',
+            'sandbox.new_session.id': str(SESSION_NEW_ID),
+            'sandbox.new_container.id': f'container-{SESSION_NEW_ID}',
             'session.id': str(SESSION_NEW_ID),
             'container.id': f'container-{SESSION_NEW_ID}',
             'sandbox.result': 'replaced',
@@ -649,6 +653,59 @@ def test_create_sandbox_error_records_observability(monkeypatch) -> None:
     assert excinfo.value in span.errors
 
 
+def test_create_sandbox_replace_stop_failure_preserves_separate_identities(
+    monkeypatch,
+) -> None:
+    now = datetime(2026, 4, 2, 12, 0, tzinfo=UTC)
+    expired_session = SandboxSession(
+        session_id=SESSION_OLD_ID,
+        chat_id=CHAT_ID,
+        container_id='container-old',
+        status=SandboxStatus.RUNNING,
+        created_at=now - timedelta(minutes=10),
+        expires_at=now,
+    )
+    repository = InMemorySandboxSessionRepository()
+    repository.save(expired_session)
+    metrics = RecordingMetrics()
+    tracer = RecordingTracer()
+    usecase = CreateSandbox(
+        repository=repository,
+        locker=FakeLocker(),
+        runtime=FailingStopRuntime('container-old'),
+        clock=FakeClock(now),
+        logger=FakeLogger(),
+        metrics=metrics,
+        tracer=tracer,
+        ttl=timedelta(minutes=5),
+    )
+    monkeypatch.setattr('usecase.sandbox._new_session_id', lambda: SESSION_NEW_ID)
+
+    with pytest.raises(RuntimeError, match='stop_failed') as excinfo:
+        usecase.execute(CreateSandboxCommand(chat_id=CHAT_ID))
+
+    _assert_increment_metric_present(
+        metrics,
+        'sandbox.create.total',
+        attrs={'result': 'error'},
+    )
+    span = _find_span(
+        tracer,
+        'usecase.create_sandbox',
+        {'chat.id': str(CHAT_ID)},
+        {
+            'sandbox.previous_session.id': str(SESSION_OLD_ID),
+            'sandbox.previous_container.id': 'container-old',
+            'sandbox.new_session.id': str(SESSION_NEW_ID),
+            'sandbox.result': 'error',
+        },
+    )
+    assert 'sandbox.new_container.id' not in span.attrs
+    assert 'session.id' not in span.attrs
+    assert 'container.id' not in span.attrs
+    assert excinfo.value in span.errors
+
+
 def test_create_sandbox_serializes_duplicate_concurrent_create_for_chat_id(
     monkeypatch,
 ) -> None: