fix-build-errors

A workflow for diagnosing and fixing failed builds, compilation, type checks, lint checks, or dependency resolution. It starts by capturing the complete error output and then addresses the earliest root cause with the smallest suitable change.

In plain words
What is it for?
Use it when npm run build, TypeScript, ESLint, compilation, dependency installation, or CI checks fail.
Why use it?
It prevents later, secondary errors from distracting you from the first real failure. It also provides a consistent way to handle differences between local builds and continuous integration checks.

Skill for Claude CodeCodex

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 skills/drvoss/everything-copilot-cli/fix-build-errors
Any agent
npx skills add drvoss/everything-copilot-cli --skill fix-build-errors
Clone the repo
git clone --depth 1 https://github.com/drvoss/everything-copilot-cli

Made for: Claude Code, Codex.

Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,110 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 $0.00032 $0.01110
Opus 5 $0.00016 $0.00555
Sonnet 5 $0.00006 $0.00222
Haiku 4.5 $0.00003 $0.00111

Measured yesterday against content hash fc84874f0fbe, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fix-build-errors 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.

skills/development/fix-build-errors/SKILL.md · 159 lines

How it starts

The opening of the file, as written. The whole thing — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Fix Build Errors

When to Use

  • Build or compilation fails after code changes
  • CI pipeline reports build failures
  • TypeScript, ESLint, or other static analysis errors
  • Dependency resolution failures after package updates
  • Build works locally but fails in CI (or vice versa)

Prerequisites

  • Access to the build command and its output
  • The project's build toolchain is installed
  • Source control so you can compare against a known-good state

Workflow

1. Capture the Full Error Output

# Run the build and capture output — use task agent to keep context clean
npm run build 2>&1 | Out-String

Or use the task agent for long builds:

task agent_type: "task"
prompt: "Run 'npm run build' and report all errors"

2. Categorize the Errors

Read errors from top to bottom — later errors are often caused by earlier ones.

Error Type Example Typical Fix
Import/Module Cannot find module 'x' Install dependency, fix path
Type Type 'string' not assignable to 'number' Fix type annotation or cast
Syntax Unexpected token Fix syntax error, check for missing brackets
Lint no-unused-vars Remove unused variable or disable rule
Config Invalid tsconfig option Fix config file
Dependency Peer dependency not met Install or update package

3. Fix the Root Cause (Not Symptoms)

# Find the first error — it's usually the root cause
npm run build 2>&1 | Select-String "error" | Select-Object -First 5

# Navigate to the file and line
# Use view tool to see context around the error

For import errors:

# Check if the module exists
glob pattern="**/*moduleName*"

# Check if it's installed
npm ls module-name 2>&1

For type errors:

# See the full type definition
grep -rn "interface|type" --include="*.ts" -A 5 src/ | Select-String "TypeName"

4. Apply the Fix

Read the full file on GitHub · 159 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 · 159 lines · 32 tokens per session scan A fc84874f0fbe

Subscribe to this mod's changes

fix-build-errors is a skill published in the GitHub repository drvoss/everything-copilot-cli (45 stars, last pushed 5d ago), licensed MIT. It adds 32 tokens to every session and 1,110 once invoked, about $0.0002 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.

Related

Other skills, from other repositories

winui-design

Use when designing, reviewing, or fixing WinUI 3: sample and control discovery with winapp find-ui, layout planning, control choice, Fluent Design alignment, Light/Dark/High Contrast theming, typography, spacing, brushes, accessibility, and XAML data-binding design. Load before authoring new XAML, reviewing UI PRs…

microsoft/win-dev-skills · 119 tokens

winui-dev-workflow

Build and run workflow for WinUI 3 apps with WinApp CLI 0.6+ — project creation with winapp new, project-mode winapp run, BuildAndRun.ps1 analyzer integration, crash diagnosis, and prerequisites. Use when creating, building, running, or fixing build errors in a WinUI 3 project.

microsoft/win-dev-skills · 73 tokens

winui-packaging

MSIX packaging, code signing, and distribution for WinUI 3 apps — build for release, certificate generation (winapp cert generate), certificate trust, code signing (winapp sign), self-contained deployment, CI/CD with GitHub Actions, and Microsoft Store submission. Use when preparing for release, creating MSIX…

microsoft/win-dev-skills · 86 tokens

winui-session-report

Analyze the current or a recent agent session (GitHub Copilot CLI or Claude Code) and generate a diagnostic report. Use only when the user explicitly asks for session feedback, agent debugging, or a review of what happened during a build session. Do not inspect session data automatically.

microsoft/win-dev-skills · 61 tokens

microsoft-build

Your companion for Microsoft Build 2026. Helps you find sessions relevant to your project, discover what's new for your tech stack, scaffold projects from sessions, and plan your event schedule. Activate when users mention sessions, schedule, what's new, Build, Ignite, AI Tour, Microsoft event, conference, or…

microsoft/Build-CLI · 109 tokens

journey-template

Create new agentic journeys from app ideas. Generates README.md (learner walkthrough), PLAN.md (AI-readable spec), and app-specific skills for OSS deployments. Supports any stack (Node.js, Python, .NET, Java, Swift, Kotlin) and Azure service (Container Apps, AKS, Functions, App Service). USE FOR: new journey, scaffold…

DanWahlin/github-azure-agentic-journeys · 153 tokens