Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add mohitmishra786/low-level-dev-skills --skill rustc-basicsgit clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/mohitmishra786/low-level-dev-skills/rustc-basics)<a href="https://agentmods.dev/skills/mohitmishra786/low-level-dev-skills/rustc-basics"><img src="https://agentmods.dev/badge/skills/mohitmishra786/low-level-dev-skills/rustc-basics/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/mohitmishra786/low-level-dev-skills/rustc-basics"><img src="https://agentmods.dev/badge/skills/mohitmishra786/low-level-dev-skills/rustc-basics.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00083 | $0.01648 |
| Opus 5 | $0.00042 | $0.00824 |
| Sonnet 5 | $0.00017 | $0.00330 |
| Haiku 4.5 | $0.00008 | $0.00165 |
Grade A, and why
rustc-basics scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 197 lines — stays where its author put it; the contents beside it link to each section on GitHub.
rustc Basics
Purpose
Guide agents through Rust compiler invocation: RUSTFLAGS, Cargo profile configuration, build modes, MIR and assembly inspection, monomorphization, and common compilation error patterns.
Triggers
- "How do I configure a release build in Rust for maximum performance?"
- "How do I see the assembly output for a Rust function?"
- "What is monomorphization and why is it making my compile slow?"
- "How do I enable LTO in Rust?"
- "My Rust binary is too large — how do I shrink it?"
- "How do I read Rust MIR output?"
Workflow
1. Choose a build mode
# Debug (default) — fast compile, no optimization, debug info
cargo build
# Release — optimized, no debug info by default
cargo build --release
# Check only (fastest, no codegen)
cargo check
# Build for specific target
cargo build --release --target aarch64-unknown-linux-gnu
2. Cargo.toml profile configuration
[profile.release]
opt-level = 3 # 0-3, "s" (size), "z" (aggressive size)
debug = false # true = full, 1 = line tables only, 0 = none
lto = "thin" # false | "thin" | true (fat LTO)
codegen-units = 1 # 1 = max optimization, higher = faster compile
panic = "abort" # "unwind" (default) | "abort" (smaller binary)
strip = "symbols" # "none" | "debuginfo" | "symbols"
overflow-checks = false # default true in debug, false in release
[profile.release-with-debug]
inherits = "release"
debug = true # release build with debug symbols
strip = "none"
[profile.dev]
opt-level = 1 # Speed up debug builds slightly
| Setting | Impact |
|---|---|
lto = true (fat) |
Best optimization, slowest link |
lto = "thin" |
Good optimization, parallel link |
codegen-units = 1 |
Best inlining, slower compile |
panic = "abort" |
Removes unwind tables, smaller binary |
opt-level = "z" |
Aggressive size reduction |
3. RUSTFLAGS
# Set for a single build
RUSTFLAGS="-C target-cpu=native" cargo build --release
# Enable all target CPU features
RUSTFLAGS="-C target-cpu=native -C target-feature=+avx2,+bmi2" cargo build --release
# Control codegen at invocation level
RUSTFLAGS="-C opt-level=3 -C codegen-units=1 -C lto=on" cargo build --release
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 197 lines · 83 tokens per session scan A 1fa7517fa571
rustc-basics is a skill published in the GitHub repository mohitmishra786/low-level-dev-skills (205 stars, last pushed 2mo ago), licensed MIT. It adds 83 tokens to every session and 1,648 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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