---
model: openai/gpt-5.6-sol
service: opencode
timestamp: 2026-08-12T03:06:08Z
git_ref: 1095e7f7
diff_cmd: git diff HEAD~1..HEAD
---

The user requested the second iterative refinement for Tractor PR 490: ensure
non-EOC failures from a shared underlying broadcast receiver do not leave peer
subscribers blocked forever, then stop for a complete commit plan.

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

Added shared terminal failure publication for ordinary `Exception` values.
The receive owner gets the original exception; peers may drain retained
values and then get a fresh `BroadcastReceiveError` chained from the original.
Late subscribers observe the same terminal state without retrying the failed
underlying receiver. Process-control and cancellation-like `BaseException`
values wake peers but are re-raised without becoming durable channel state.

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

Exported `BroadcastReceiveError` as the public peer-delivery exception.

> `git diff HEAD~1..HEAD -- docs/api/trionics.rst`

Documented `BroadcastReceiveError` and the owner-versus-peer delivery
contract, including retained-value draining and late subscribers.

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

Added deterministic bounded regressions. One scripts a successful receive
followed by `RuntimeError`, proving the root drains retained data, all current
and late receivers observe terminal failure, and the source is not retried.
The second scripts a custom `BaseException`, proving peers wake and take over
the next source receive without retaining control-flow state.

Verification output:

```text
.............                                                            [100%]
13 passed in 5.62s
```

Python compilation and `git diff --check` passed. Iterative adversarial review
drove independent peer exception wrappers, ordinary-versus-control-flow
classification, bounded test completion, public docs, and the final catch-all
peer wake. Final review found no issues.