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Kodelyth ECC
Command

/rust-build

Fix Rust build errors, borrow checker issues, and dependency problems incrementally. Invokes the rust-build-resolver agent for minimal, surgical fixes.

Run:/rust-build

Rust Build and Fix

This command invokes the rust-build-resolver agent to incrementally fix Rust build errors with minimal changes.

What This Command Does

  • Run Diagnostics: Execute cargo check, cargo clippy, cargo fmt --check
  • Parse Errors: Identify error codes and affected files
  • Fix Incrementally: One error at a time
  • Verify Each Fix: Re-run cargo check after each change
  • Report Summary: Show what was fixed and what remains

When to Use

Use /rust-build when:

  • cargo build or cargo check fails with errors
  • cargo clippy reports warnings
  • Borrow checker or lifetime errors block compilation
  • Cargo dependency resolution fails
  • After pulling changes that break the build

Diagnostic Commands Run

# Primary build check
cargo check 2>&1
Lints and suggestions

cargo clippy -- -D warnings 2>&1
Formatting check

cargo fmt --check 2>&1
Dependency issues

cargo tree --duplicates
Security audit (if available)

if command -v cargo-audit >/dev/null; then cargo audit; else echo "cargo-audit not installed"; fi

Example Session

User: /rust-build
Agent:

Rust Build Resolution
Initial Diagnostics
bash $ cargo check error[E0502]: cannot borrow map as mutable because it is also borrowed as immutable --> src/service/cache.rs:25:5 error[E0308]: mismatched types --> src/handler/api.rs:42:12 error[E0425]: cannot find value db in this scope --> src/handler/api.rs:58:9 

Errors found: 3
Fix 1: Borrow Checker Error
File: src/service/cache.rs:25
Error: E0502 — cannot borrow map as mutable because also borrowed as immutable
Cause: Immutable borrow still active during mutable insert
rust // Changed: restructured to end immutable borrow before mutable access if !map.contains_key("key") { map.insert("key".into(), default); }
bash $ cargo check

2 errors remaining



Fix 2: Type Mismatch
File: src/handler/api.rs:42
Error: E0308 — mismatched types: expected usize, found &str
rust // Changed let count = params.get("count"); // To let count: usize = params.get("count") .and_then(|s| s.parse().ok()) .unwrap_or(0);
bash $ cargo check

1 error remaining



Fix 3: Unresolved Name
File: src/handler/api.rs:58
Error: E0425 — cannot find value db in this scope
Cause: Missing import
rust // Added use crate::db;
bash $ cargo check

Build successful!



Final Verification
bash $ cargo clippy -- -D warnings

No warnings

$ cargo test running 6 tests test service::cache::tests::test_insert ... ok test service::cache::tests::test_get ... ok test handler::api::tests::test_parse_count ... ok test handler::api::tests::test_missing_count ... ok test handler::api::tests::test_db_import ... ok test handler::api::tests::test_response ... ok

test result: ok. 6 passed; 0 failed; 0 ignored 



Summary
| Metric | Count |
|--------|-------|
| Build errors fixed | 3 |
| Clippy warnings fixed | 0 |
| Files modified | 2 |
| Remaining issues | 0 |
Build Status: SUCCESS

Common Errors Fixed

| Error | Typical Fix | |-------|-------------| | cannot borrow as mutable | Restructure to end immutable borrow first; clone only if justified | | does not live long enough | Use owned type or add lifetime annotation | | cannot move out of | Restructure to take ownership; clone only as last resort | | mismatched types | Add .into(), as, or explicit conversion | | trait X not implemented | Add #[derive(Trait)] or implement manually | | unresolved import | Add to Cargo.toml or fix use path | | cannot find value | Add import or fix path |

Fix Strategy

  • Build errors first - Code must compile
  • Clippy warnings second - Fix suspicious constructs
  • Formatting third - cargo fmt compliance
  • One fix at a time - Verify each change
  • Minimal changes - Don't refactor, just fix

Stop Conditions

The agent will stop and report if:

  • Same error persists after 3 attempts
  • Fix introduces more errors
  • Requires architectural changes
  • Borrow checker error requires redesigning data ownership

Related Commands

  • /rust-test - Run tests after build succeeds
  • /rust-review - Review code quality
  • /verify - Full verification loop

Related

  • Agent: agents/rust-build-resolver.md
  • Skill: skills/rust-patterns/

Agents this command fires

rust-build-resolver

Related skills

rust-patterns
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