Step A of the `._ria_nursery` removal (issue #477 follow-up, see
`ai/conc-anal/ria_nursery_removal_plan.md`): `.run_in_actor()`
children now spawn via the default daemon nursery and their
result-reaping moves up into the `ActorNursery` machinery,
- new `_supervise._reap_ria_portals()`: one
`_spawn.cancel_on_completion()` task per ria child, run AFTER
`._join_procs` is set — replacing the per-child reaper task the
backends formerly spawned (keyed off
`._cancel_after_result_on_exit` membership) which required
routing such children into `._ria_nursery`.
- happy path: reap awaited right after `._join_procs.set()`,
preserving "collect ria results before daemon join" sequencing.
- error path: snapshot ria `(portal, subactor)` pairs (backend
`finally`s pop `._children` as procs reap), `await an.cancel()`,
THEN a 0.5s-bounded reap over the snapshot; anything collectable
is already queued in the local ctx and a parked reaper
self-cleans (`trio.Cancelled` results are never stashed). NB: a
concurrent reap+cancel variant deadlocked `test_multierror` and
a 3s bound blew `test_cancel_while_childs_child_in_sync_sleep`'s
deadline — deats in the plan doc's probe history.
- `spawn/_trio.py` + `spawn/_mp.py`: drop the membership branch,
per-child reaper nursery + now-unused `cancel_on_completion`
imports; the join phase is a bare `soft_kill()`.
`._ria_nursery` is now vestigial (zero spawn users): step B
deletes it + `start_actor()`'s `nursery=` escape hatch and merges
the supervisor's two error handlers.
Prompt-IO: ai/prompt-io/claude/20260702T165806Z_a34aaf98_prompt_io.md
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Gud Boi
4a4076cef1