--- 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