---
model: openai/gpt-5.6-sol
service: opencode
timestamp: 2026-08-19T02:07:57Z
git_ref: b38efed7
diff_cmd: git diff HEAD~1..HEAD
---

Fix the final PR #481 review finding: `runtime_kwargs` is mutually
exclusive with both caller placement options whenever it is provided,
including an empty dict.

> `git diff HEAD~1..HEAD -- tractor/to_actor/_api.py tests/test_to_actor.py`

Use an explicit `is not None` check rather than dict truthiness. Expand
the validation regression across `an=` and `portal=`, each with empty
and configured runtime kwargs, so every invalid combination fails
before actor runtime startup.

Verification:

- Trio/TCP: `23 passed`
- Trio/UDS: `23 passed`
- `mp_spawn`/TCP: `23 passed`
- Ruff and `git diff --check`: clean
