# Agent instructions
## Testing
- **Use `cargo nextest run` instead of `cargo test`.**
- Filter examples:
- `cargo nextest run -E 'test(method_kwargs)'`
- `cargo nextest run --lib`
- `cargo nextest run --all-targets`
- Do not default to `cargo test` unless nextest is unavailable and you note why.
## Recursion tests and native stack
Each Python call frame currently costs a large amount of native stack
(`Box::pin` futures hold full match-arm state). Prefer:
- Setting `InterpreterConfig::max_recursion_depth` **below** the host stack
ceiling so tests observe `RecursionError` rather than SIGABRT.
- After per-arm boxed futures, default-thread recursion is ~8–12 levels; keep
"under cap" tests at ≤6 and RecursionError tests with max_recursion_depth
below ~12 so the interpreter guard fires before SIGABRT.
Do not raise default-thread recursion smoke depths without profiling stack use.