Clean marked trial engine processes

tests/test_core_flow.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import json
 import os
+import signal
 import subprocess
 import tempfile
 import unittest
@@ -4573,6 +4574,26 @@ class CoreFlowTests(unittest.TestCase):
         self.assertEqual(mock_killpg.call_args_list[0].args[0], 1234)
         process.wait.assert_not_called()
 
+    def test_terminate_process_tree_signals_marker_processes_when_group_missing(self) -> None:
+        process = mock.Mock()
+        process.pid = 1234
+        process.poll.return_value = 0
+        marker_env = {"AITUNER_TRIAL_ID": "trial-0001"}
+        with mock.patch("aituner.worker.os.getpgid", side_effect=ProcessLookupError):
+            with mock.patch("aituner.worker.os.killpg", side_effect=ProcessLookupError):
+                with mock.patch(
+                    "aituner.worker._pids_matching_env",
+                    side_effect=[[2222], []],
+                ) as mock_pids:
+                    with mock.patch("aituner.worker._signal_pids") as mock_signal:
+                        _terminate_process_tree(
+                            process,
+                            timeout_s=1.0,
+                            marker_env=marker_env,
+                        )
+        self.assertEqual(mock_pids.call_args_list[0].args[0], marker_env)
+        self.assertEqual(mock_signal.call_args_list[0].args, ([2222], signal.SIGTERM))
+
     def test_openai_url_avoids_double_v1(self) -> None:
         self.assertEqual(
             _openai_url("http://example.com", "/v1/chat/completions"),