---
model: openai/gpt-5.6-sol
service: opencode
timestamp: 2026-08-13T18:19:01Z
git_ref: a2e0df4b
diff_cmd: git diff HEAD~1..HEAD
---

The user asked to continue after committing the paired piker EMS consumer
fix. The next isolated Tractor PR 490 item was to clean cancelled-task
diagnostics and define zero-buffer broadcast behavior, then review, test and
stop at a complete commit plan.

> `git diff HEAD~1..HEAD -- tractor/trionics/_broadcast.py`

Made `BroadcastState.cancelled` transient: receiver progress and close clear
that receiver's diagnostic, terminal EOC and shared receive failure clear all
stale cancelled tasks, and durable EOC prevents peers from re-entering the
closed source. `broadcast_receiver()` now rejects non-positive retention
capacity before creating an unusable zero-length deque.

> `git diff HEAD~1..HEAD -- tractor/_streaming.py`

Made explicit `MsgStream.aclose()` release its internally allocated root
broadcaster while preserving graceful receive-internal EOC teardown. Used a
task-local marker so the public zero-argument `aclose()` signature and valid
subclass overrides remain compatible.

> `git diff HEAD~1..HEAD -- tractor/to_asyncio.py`

Made `LinkedTaskChannel.aclose()` release its internally allocated root
broadcaster before closing the underlying Trio receive channel.

> `git diff HEAD~1..HEAD -- tests/test_task_broadcasting.py`

Added synchronized regressions for transient child cancellation diagnostics,
cross-receiver terminal cleanup, durable EOC peer wakeups, root broadcaster
cleanup through both public wrappers, `MsgStream.aclose()` subclass
compatibility, and zero-buffer rejection.

Verification output:

```text
...........................                                              [100%]
27 passed in 5.89s

.                                                                        [100%]
1 passed in 1.22s

.                                                                        [100%]
1 passed in 0.88s
```

The integration runs cover real `MsgStream` actor fan-out and infected-asyncio
`LinkedTaskChannel` fan-out. Ruff, Python compilation and `git diff --check`
passed. Repeated adversarial review found and resolved root close re-entrancy,
cross-receiver terminal retention, durable-EOC and subclass-compatibility
issues; final review reported no findings.