fix: finalize cancelled fix agents

yoni-at-strix · Sep 25, 2026 · Sep 25, 2026 · Sep 25, 2026 · Sep 25, 2026 · Sep 25, 2026
commit 3763a677f94a05ff3b7fcaf1081e6d55aafdb7c1
diff --git a/strix/core/execution.py b/strix/core/execution.py
@@ -21,6 +21,7 @@
 )
 
 from strix.config import codex
+from strix.core.agents import TERMINAL_STATUSES, Status
 from strix.core.hooks import (
     BudgetExceededError,
     BudgetPausedError,
@@ -47,7 +48,7 @@
     from agents.memory import Session, SQLiteSession
     from agents.result import RunResultBase
 
-    from strix.core.agents import AgentCoordinator, Status
+    from strix.core.agents import AgentCoordinator
 
 
 logger = logging.getLogger(__name__)
@@ -1104,6 +1105,8 @@ async def _child_loop() -> None:
         # spurious "Task exception was never retrieved" warning. The root agent
         # hits the same limit on its next call and tears the scan down.
         result = None
+        terminal_status: Status = "completed"
+        terminal_error = None
         try:
             result = await run_agent_loop(
                 agent=child_agent,
@@ -1119,18 +1122,49 @@ async def _child_loop() -> None:
                 event_sink=event_sink,
                 hooks=hooks,
             )
+        except asyncio.CancelledError:
+            terminal_status = "stopped"
+            raise
         except BudgetExceededError:
+            terminal_status = "stopped"
             logger.info("child %s stopped after reaching the scan budget limit", child_id)
         except SubagentBudgetReservedError:
+            terminal_status = "stopped"
             logger.info("child %s stopped at the sub-agent budget reserve", child_id)
+        except Exception as error:
+            terminal_status = "crashed"
+            terminal_error = request_log.failure_text(error)
+            raise
         finally:
-            if on_complete is not None:
-                try:
-                    await on_complete(result, session)
-                except Exception:
-                    logger.exception("child %s completion delivery failed", child_id)
-            if not coordinator.is_shutting_down:
-                await _notify_parent_on_exit(coordinator, child_id)
+            try:
+                if on_complete is not None:
+                    try:
+                        await on_complete(result, session)
+                    except asyncio.CancelledError:
+                        terminal_status = "stopped"
+                        raise
+                    except Exception:
+                        logger.exception("child %s completion delivery failed", child_id)
+            finally:
+                await _settle_child_exit(
+                    coordinator,
+                    child_id,
+                    terminal_status,
+                    terminal_error,
+                )
 
     task_handle = asyncio.create_task(_child_loop(), name=f"agent-{name}-{child_id}")
     await coordinator.attach_runtime(child_id, task=task_handle)
+
+
+async def _settle_child_exit(
+    coordinator: AgentCoordinator,
+    child_id: str,
+    terminal_status: Status,
+    terminal_error: str | None,
+) -> None:
+    status = await _agent_status(coordinator, child_id)
+    if status not in TERMINAL_STATUSES:
+        await coordinator.set_status(child_id, terminal_status, error=terminal_error)
+    if not coordinator.is_shutting_down:
+        await _notify_parent_on_exit(coordinator, child_id)
diff --git a/strix/fix/scan.py b/strix/fix/scan.py
@@ -143,10 +143,7 @@ async def _dispatch(self, finding_id: str) -> None:
                 parent_history=[],
             )
         except Exception as error:  # noqa: BLE001 - report launch failure to the scan
-            active = self.tasks.get(finding_id)
-            if active and not active.done():
-                active.cancel()
-                await asyncio.gather(active, return_exceptions=True)
+            await self._cancel_active(finding_id)
             logger.warning("fix.dispatch finding=%s rejected=%s", finding_id, error)
             await self.coordinator.send(
                 self._parent_ctx["agent_id"],
@@ -235,8 +232,7 @@ async def _spawn(self, finding_id: str, spawn: Any, **kwargs: Any) -> dict[str,
                 previous.get("reason") or "The previous Fix attempt failed; it was not restarted."
             )
         if running and not running.done():
-            running.cancel()
-            await asyncio.gather(running, return_exceptions=True)
+            await self._cancel_active(finding_id)
         used = int(previous.get("turns", 0))
         if used >= 300:
             raise ValueError("This finding has exhausted its 300-turn Fix allowance.")
@@ -421,10 +417,18 @@ async def close(self) -> None:
         for task in self.dispatches:
             task.cancel()
         await asyncio.gather(*self.dispatches, return_exceptions=True)
-        for task in self.tasks.values():
-            if not task.done():
-                task.cancel()
-        await asyncio.gather(*self.tasks.values(), return_exceptions=True)
+        for finding_id in list(self.tasks):
+            await self._cancel_active(finding_id)
+
+    async def _cancel_active(self, finding_id: str) -> None:
+        task = self.tasks.get(finding_id)
+        if task is None or task.done():
+            return
+        agent_id = self.records.get(finding_id, {}).get("agent_id")
+        if agent_id:
+            await self.coordinator.set_status(agent_id, "stopped")
+        task.cancel()
+        await asyncio.gather(task, return_exceptions=True)
 
     async def _stage_base(self, source: Path) -> str:
         key = hashlib.sha256(str(source).encode()).hexdigest()[:16]

diff --git a/tests/test_execution.py b/tests/test_execution.py
@@ -5,10 +5,11 @@
 import asyncio
 import contextlib
 import json
-from typing import Any, cast
+from typing import TYPE_CHECKING, Any, cast
 from unittest.mock import MagicMock
 
 import pytest
+from agents import RunConfig
 from agents.exceptions import MaxTurnsExceeded
 from agents.items import MessageOutputItem
 from agents.memory import SQLiteSession
@@ -19,13 +20,18 @@
 from strix.core.agents import AgentCoordinator
 from strix.core.execution import (
     _notify_root_on_budget_reserve,
+    _start_child_runner,
     notify_parent_on_terminal,
 )
 from strix.core.sessions import seed_initial_input
 from strix.tools.agents_graph.tools import agent_finish, stop_agent
 from strix.tools.finish.tool import finish_scan
 
 
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
 _NO_STREAM_EVENTS: list[Any] = []
 
 
@@ -143,6 +149,85 @@ async def test_concurrent_reserve_claims_yield_single_root() -> None:
     assert all(r is None for r in results if r != "root")
 
 
+@pytest.mark.asyncio
+async def test_cancelled_native_child_is_always_terminal(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    coordinator = AgentCoordinator()
+    await coordinator.register("root", "strix", parent_id=None)
+    await coordinator.register("child", "fix", parent_id="root")
+    started = asyncio.Event()
+
+    async def run_forever(**_kwargs: Any) -> None:
+        started.set()
+        await asyncio.Event().wait()
+
+    monkeypatch.setattr(execution, "run_agent_loop", run_forever)
+    sessions: list[SQLiteSession] = []
+    await _start_child_runner(
+        parent_ctx={"agent_id": "root", "parent_id": None},
+        coordinator=coordinator,
+        agents_db_path=tmp_path / "agents.sqlite",
+        sessions_to_close=sessions,
+        run_config=RunConfig(tracing_disabled=True),
+        max_turns=10,
+        interactive=False,
+        child_agent=MagicMock(),
+        child_id="child",
+        name="fix",
+        parent_id="root",
+        task="repair",
+        initial_input=[],
+    )
+    await started.wait()
+    task = coordinator.runtimes["child"].task
+    assert task is not None
+    task.cancel()
+    await asyncio.gather(task, return_exceptions=True)
+
+    assert coordinator.statuses["child"] == "stopped"
+    for session in sessions:
+        session.close()
+
+
+@pytest.mark.asyncio
+async def test_crashed_native_child_is_always_terminal(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    coordinator = AgentCoordinator()
+    await coordinator.register("root", "strix", parent_id=None)
+    await coordinator.register("child", "fix", parent_id="root")
+
+    async def crash(**_kwargs: Any) -> None:
+        raise RuntimeError("repair crashed")
+
+    monkeypatch.setattr(execution, "run_agent_loop", crash)
+    sessions: list[SQLiteSession] = []
+    await _start_child_runner(
+        parent_ctx={"agent_id": "root", "parent_id": None},
+        coordinator=coordinator,
+        agents_db_path=tmp_path / "agents.sqlite",
+        sessions_to_close=sessions,
+        run_config=RunConfig(tracing_disabled=True),
+        max_turns=10,
+        interactive=False,
+        child_agent=MagicMock(),
+        child_id="child",
+        name="fix",
+        parent_id="root",
+        task="repair",
+        initial_input=[],
+    )
+    task = coordinator.runtimes["child"].task
+    assert task is not None
+    await asyncio.gather(task, return_exceptions=True)
+
+    assert coordinator.statuses["child"] == "crashed"
+    assert coordinator.errors["child"] == "repair crashed"
+    for session in sessions:
+        session.close()
+
+
 @pytest.mark.asyncio
 async def test_claim_reserve_sets_flag_and_wakes_parked_agents() -> None:
     coordinator = AgentCoordinator()

diff --git a/tests/test_scan_fixes.py b/tests/test_scan_fixes.py
@@ -7,6 +7,7 @@
 import asyncio
 from pathlib import Path
 from types import SimpleNamespace
+from typing import Any
 from unittest.mock import AsyncMock, Mock
 
 import pytest
@@ -17,7 +18,11 @@
 from strix.core.agents import AgentCoordinator
 from strix.core.execution import spawn_child_agent
 from strix.core.hooks import ReportUsageHooks
-from strix.fix import FindingContext
+from strix.fix import (
+    FindingContext,
+    FixPreparationResultV1,
+    PreparationState,
+)
 from strix.fix import scan as scan_module
 from strix.fix.scan import ScanFixes
 from strix.fix.session import WorktreeSession
@@ -188,12 +193,27 @@ async def test_finding_revision_invalidates_active_completion(tmp_path):
     assert not fixes._current("finding", digest)
 
 
+@pytest.mark.asyncio
+async def test_superseded_fix_agent_is_marked_stopped_before_cancellation(tmp_path):
+    fixes, _, _, _, _, _, _ = setup(tmp_path)
+    await fixes.coordinator.register("old-fix", "Fix", "reporter", skills=["fix_task"])
+    await fixes.coordinator.mark_running("old-fix")
+    task = asyncio.create_task(asyncio.Event().wait())
+    fixes.records["finding"] = {"agent_id": "old-fix", "status": "running"}
+    fixes.tasks["finding"] = task
+
+    await fixes._cancel_active("finding")
+
+    assert fixes.coordinator.statuses["old-fix"] == "stopped"
+    assert task.cancelled()
+
+
 @pytest.mark.parametrize("change", ["revised", "withdrawn", "unconfirmed"])
 async def test_finding_changed_before_delivery_discards_reviewed_patch(
     tmp_path, monkeypatch, change
 ):
     fixes, report, _, _, reports, context, _ = setup(tmp_path)
-    callback = None
+    callback: Any = None
 
     async def spawn(**kwargs):
         nonlocal callback
@@ -211,8 +231,8 @@ async def finish_preparation(request, _env, _hooks, _result, _session, artifact)
             reports.clear()
         else:
             report["validation_status"] = "unconfirmed"
-        return scan_module.FixPreparationResultV1(
-            state="ready",
+        return FixPreparationResultV1(
+            state=PreparationState.READY,
             stop_reason="Approved.",
             source_identity=request.candidate.source_identity,
             candidate=request.candidate,