# Rust Failure Modes

> Rules for writing or editing Rust code. Forbids

- Skill: `tomevault-io/rust-failure-modes` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/rust-failure-modes`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/rust-failure-modes/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/rust-failure-modes

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Apply these rules when touching `.rs` files. Full rationale: [`.claude/rules/rust-llm-failures.md`](../../rules/rust-llm-failures.md).

1. **No `#[allow(clippy::*)]` without `// reason: ...`.** Fix the lint first; suppress only with documented justification next to the attribute.
2. **No `.clone()` to escape the borrow checker.** Try `&T`, lifetime restructuring, ownership change, `Cow<T>`, or `Arc<T>` first. "Compiler complained" is not a reason.
3. **No `.unwrap()` / `.expect()` outside `#[cfg(test)]` or `tests/`.** Use `?` and `Result<T, E>`. Exceptions: provably impossible invariant with `// reason:` comment, or initialization-time unrecoverable failure (intentional panic). Performance-critical and safety-critical code: zero tolerance.

If tempted to break any rule, stop and ask the user. Do not silently bypass with a suppression.

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> Source: [junhjang/claude-harness](https://github.com/junhjang/claude-harness) — distributed by [TomeVault](https://tomevault.io).
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