m03-mutability SKILL.md skillA
m03-mutability from moeru-ai/auv is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add moeru-ai/auv/m03-mutability@git:20260725.8a8e541Pins git:20260725.8a8e541 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- moeru-ai/auv
- Path
.agents/skills/m03-mutability/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260725.8a8e541, committed Jul 25, 2026
- Size
- 4,157 bytes
- Repository stars
- 202
- License
- Apache-2.0
CRITICAL: Use for mutability issues. Triggers: E0596, E0499, E0502, cannot borrow as mutable, already borrowed as immutable, mut, &mut, interior mutability, Cell, RefCell, Mutex, RwLock, 可变性, 内部可变性, 借用冲突.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Mutability > **Layer 1: Language Mechanics** ## Core Question **Why does this data need to change, and who can change it?** Before adding interior mutability, understand: - Is mutation essential or accidental complexity? - Who should control mutation? - Is the mutation pattern safe? --- ## Error → Design Question | Error | Don't Just Say | Ask Instead | |-------|----------------|-------------| | E0596 | "Add mut" | Should this really be mutable? | | E0499 | "Split borrows" | Is the data structure right? | | E0502 | "Separate scopes" | Why do we need both borrows? | | RefCell panic | "Use try_borrow" | Is runtime check appropriate? | --- ## Thinking Prompt Before adding mutability: 1. **Is mutation necessary?** - Maybe transform → return new value - Maybe builder → construct immutably 2. **Who controls mutation?** - External caller → `&mut T` - Internal logic → interior mutability - Concurrent access → synchronized mutability 3. **What's the thread context?** - Single-thread → Cell/RefCell - Multi-thread → Mutex/RwLock/Atomic --- ## Trace Up ↑ When mutability conflicts persist: ``` E0499/E0502 (borrow conflicts) …
Read the whole file at its exact version.
How to install
mdr add moeru-ai/auv/m03-mutability@sha256:1e2d270dbfd28412The line at the top of this page pins the label git:20260725.8a8e541, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_26j64zwx6iuonmqq)
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Versions
The registry has recorded 1 version of this file, committed on Jul 25, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4157 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
moeru-ai/auv · 202 stars · license Apache-2.0 · pushed 2026-11-04 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_26j64zwx6iuonmqq GET https://markdownregistry.com/api/v1/resolve?ref=moeru-ai/auv/m03-mutability GET https://markdownregistry.com/api/v1/blob/1e2d270dbfd2841238783bcfed109fbf6b67e4132d698a4a015232a217078c23
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.