build-error-resolver

A build-failure agent that diagnoses and fixes compilation, type-checking, and build errors in several programming languages. It groups related messages to find the underlying cause instead of treating every follow-on error separately.

In plain words
What is it for?
Use it when commands such as npm run build, TypeScript, Go, Rust, or .NET builds fail, when type checks report errors, or when CI breaks after a refactor or dependency update.
Why use it?
It reduces the time spent tracing error output and verifies whether the project builds successfully after the fix.

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/drvoss/everything-copilot-cli/build-error-resolver
Clone the repo
git clone --depth 1 https://github.com/drvoss/everything-copilot-cli
Per session 19 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,550 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00019 $0.01550
Opus 5 $0.00010 $0.00775
Sonnet 5 $0.00004 $0.00310
Haiku 4.5 $0.00002 $0.00155

Measured 2d ago against content hash d530ce7a7026, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

build-error-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 2d 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.

agents/build-error-resolver.md · 186 lines

How it starts

The opening of the file, as written. The whole thing — 186 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Build Error Resolver Agent

Purpose

The Build Error Resolver agent takes build, compilation, or type-checking output that contains errors and systematically resolves them. It parses error messages, identifies root causes, applies targeted fixes, and verifies the build succeeds.

This is a fast, focused agent that uses the task agent type for efficient command execution with minimal output on success and full diagnostics on failure.

When to Use

  • A build command fails (npm run build, tsc, go build, cargo build, dotnet build)
  • TypeScript/ESLint/Pyright reports type errors
  • CI/CD pipeline fails with compilation errors
  • After a dependency update breaks types or imports
  • After a large refactor introduces broken references
  • When the user pastes error output and asks to "fix this"

How It Works

  1. Capture errors – Run the build command and collect the full error output.
  2. Parse – Extract structured information from each error:
    • File path and line number
    • Error code (e.g., TS2345, E0308, CS1061)
    • Error message
    • Related/caused-by chain
  3. Categorize – Group errors by root cause. Many errors cascade from a single issue. Fix root causes first.
  4. Fix – Apply the minimal, surgical fix for each root cause:
    • Missing imports → add the import
    • Type mismatches → correct the type or add proper conversion
    • Missing properties → add required fields
    • Deleted references → update to new API or remove usage
  5. Verify – Re-run the build to confirm all errors are resolved and no new ones appeared.
  6. Iterate – If new errors appear after fixing, repeat the cycle.

Copilot CLI Integration

  • agent_type: task – optimized for command execution. Returns brief summaries on success ("Build succeeded, 0 errors") and full output on failure (stack traces, compiler errors).
  • Model: Uses gpt-5-mini for fast, cost-effective error resolution. Most build errors don't need premium reasoning.
  • Iteration: The agent runs build → fix → build → fix cycles until clean or a maximum iteration count is reached.

Read the full file on GitHub · 186 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. 2d ago First seen · 186 lines · 19 tokens per session scan A d530ce7a7026

Subscribe to this mod's changes

build-error-resolver is an agent published in the GitHub repository drvoss/everything-copilot-cli (45 stars, last pushed 5d ago), licensed MIT. It adds 19 tokens to every session and 1,550 once invoked, about $0.0001 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 2026-08-30.