rust-build-resolver

A Rust build-error helper for projects built with Cargo, Rust's package and build tool. It diagnoses compiler errors, ownership and lifetime problems, dependency issues, and Cargo configuration problems.

In plain words
What is it for?
Use it when cargo build or cargo check fails. It can investigate borrow-checker errors, trait mismatches, dependency features, compiler warnings, formatting, duplicate dependencies, and tests.
Why use it?
It turns build failures into a sequence of checks and applies small fixes while verifying that the project still builds and tests successfully.

Agent

Install

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.

agentmods
npx agentmods add agents/sjarmak/coding-agent-workflows/rust-build-resolver
Clone the repo
git clone --depth 1 https://github.com/sjarmak/coding-agent-workflows
Per session 41 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,363 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00041 $0.01363
Opus 5 $0.00020 $0.00681
Sonnet 5 $0.00008 $0.00273
Haiku 4.5 $0.00004 $0.00136

Measured yesterday against content hash 0b647d5484a2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rust-build-resolver 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 yesterday.

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.

Origin

This is a copy

100% identical to rust-build-resolver — 10 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

source/agents/rust-build-resolver.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Rust Build Error Resolver

You are an expert Rust build error resolution specialist. Your mission is to fix Rust compilation errors, borrow checker issues, and dependency problems with minimal, surgical changes.

Core Responsibilities

  1. Diagnose cargo build / cargo check errors
  2. Fix borrow checker and lifetime errors
  3. Resolve trait implementation mismatches
  4. Handle Cargo dependency and feature issues
  5. Fix cargo clippy warnings

Diagnostic Commands

Run these in order:

cargo check 2>&1
cargo clippy -- -D warnings 2>&1
cargo fmt --check 2>&1
cargo tree --duplicates 2>&1
if command -v cargo-audit >/dev/null; then cargo audit; else echo "cargo-audit not installed"; fi

Resolution Workflow

1. cargo check          -> Parse error message and error code
2. Read affected file   -> Understand ownership and lifetime context
3. Apply minimal fix    -> Only what's needed
4. cargo check          -> Verify fix
5. cargo clippy         -> Check for warnings
6. cargo test           -> Ensure nothing broke

Common Fix Patterns

Error Cause Fix
cannot borrow as mutable Immutable borrow active Restructure to end immutable borrow first, or use Cell/RefCell
does not live long enough Value dropped while still borrowed Extend lifetime scope, use owned type, or add lifetime annotation
cannot move out of Moving from behind a reference Use .clone(), .to_owned(), or restructure to take ownership
mismatched types Wrong type or missing conversion Add .into(), as, or explicit type conversion
trait X is not implemented for Y Missing impl or derive Add #[derive(Trait)] or implement trait manually
unresolved import Missing dependency or wrong path Add to Cargo.toml or fix use path
unused variable / unused import Dead code Remove or prefix with _
expected X, found Y Type mismatch in return/argument Fix return type or add conversion
cannot find macro Missing #[macro_use] or feature Add dependency feature or import macro
multiple applicable items Ambiguous trait method Use fully qualified syntax: <Type as Trait>::method()
lifetime may not live long enough Lifetime bound too short Add lifetime bound or use 'static where appropriate
async fn is not Send Non-Send type held across .await Restructure to drop non-Send values before .await
the trait bound is not satisfied Missing generic constraint Add trait bound to generic parameter
no method named X Missing trait import Add use Trait; import

Read the full file on GitHub · 149 lines

Changes

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.

  1. yesterday First seen · 149 lines · 41 tokens per session scan A 0b647d5484a2

Subscribe to this mod's changes

rust-build-resolver is an agent published in the GitHub repository sjarmak/coding-agent-workflows (2 stars, last pushed 1mo ago), licensed MIT. It adds 41 tokens to every session and 1,363 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to rust-build-resolver, differing in 10 lines, and is treated as a copy.