Cc rust-dev

This skill should be used when working with Rust code, reviewing Rust code, managing Rust dependencies, creating Rust projects, or fixing Rust compilation errors. It provides strict coding standards (especially FAIL FAST error handling), workspace architecture guidance, dependency management automation, and common Rust patterns.

install

source · Clone the upstream repo

git clone https://github.com/onsails/cc

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/onsails/cc "$T" && mkdir -p ~/.claude/skills && cp -r "$T/rust-dev/skills/rust-dev" ~/.claude/skills/onsails-cc-rust-dev && rm -rf "$T"

manifest: rust-dev/skills/rust-dev/SKILL.md

source content

Rust Development

Core Rules

Edition 2024: Always
```
edition = "2024"
```
in Cargo.toml
FAIL FAST: Every error MUST propagate with
```
?
```
or
```
return Err
```
. Logging is NOT handling. See error-handling.md

Dependency versions: Use

x.x

format (e.g.,

serde = "1.0"

). Find latest with

python3 scripts/check_crate_version.py <crate>

Workspace architecture: Root Cargo.toml defines workspace only. Separate crates for lib/cli/client
Error types:
```
thiserror
```
(with backtrace) for libraries,
```
anyhow
```
for binaries/tests
CLI-first config: Never bypass CLI args. Use
```
from_cli_args()
```
, never
```
Default
```
that reads env
No
env::set_var
in tests: Pass config through function parameters
Async: Use tokio consistently
Visibility: Private (default) >
```
pub(crate)
```
>
```
pub
```
No magic numbers: Use
```
const
```
or CLI args

Adding Dependencies

Run

python3 scripts/check_crate_version.py <crate-name>

to find latest version

Add to
```
[workspace.dependencies]
```
in root Cargo.toml with
```
x.x
```
format
Reference in member crates:
```
serde = { workspace = true }
```

Common deps:

thiserror = "2.0"

anyhow = "1.0"

tokio = { version = "1", features = ["full"] }

serde = { version = "1.0", features = ["derive"] }

clap = { version = "4.5", features = ["derive"] }

Creating New Projects

Use the template in

assets/workspace-template/

project/
├── Cargo.toml              # Workspace root, no code
├── project/                # Library crate (thiserror)
│   ├── Cargo.toml
│   └── src/lib.rs
└── project-cli/            # Binary crate (anyhow + clap)
    ├── Cargo.toml
    └── src/main.rs

Module Organization

Split modules when file exceeds ~500 lines or tests take 50%+ of file. See module-organization.md for patterns.

Error Handling

The most critical standard. See error-handling.md for full rules and examples.

Quick check: If you see

if let Err

match ... Err

without

return Err

, it's a bug.

References

error-handling.md — FAIL FAST rules, thiserror/anyhow patterns, error chain preservation
module-organization.md — When/how to split modules, test extraction
dependency-guide.md — Workspace deps, feature flags, common crates

Scripts

```
scripts/check_crate_version.py
```
— Query crates.io for latest dependency versions