Build failed with 1 error
Module not found: Can't resolve './components/Header'
Type error: Property 'x' does not exist on type 'Y'

Your JavaScript build (Vite, Webpack, Next.js, Astro) failed. Here are the most common causes.

Fix 1: Module Not Found

# ❌ Importing a file that doesn't exist
import Header from './components/Header';  # 💥 Wrong path

# ✅ Check the actual file path and extension
ls src/components/Header.*

# Common issues:
# - Case sensitivity: Header vs header (Linux is case-sensitive)
# - Missing extension: ./utils vs ./utils.ts
# - Wrong relative path: ../ vs ./

Fix 2: TypeScript Type Error

# ❌ Build fails on type errors
# ✅ Fix the type error, or temporarily skip type checking

# Next.js — skip type checking in build
# next.config.js
module.exports = {
    typescript: { ignoreBuildErrors: true },  // Temporary!
};

# Vite — type checking is separate
npx tsc --noEmit  # Check types without building

Fix 3: Out of Memory During Build

# ❌ Large project runs out of memory
FATAL ERROR: JavaScript heap out of memory

# ✅ Increase Node memory
NODE_OPTIONS="--max-old-space-size=4096" npm run build

Fix 4: Dependency Issue

# ❌ Package version conflict
# ✅ Clean install
rm -rf node_modules package-lock.json .next dist
npm install
npm run build

Fix 5: Environment Variable Missing

# ❌ Build expects env vars that aren't set
# ✅ Check your .env file exists
# Vite: must prefix with VITE_
# Next.js: must prefix with NEXT_PUBLIC_ for client-side

# Or provide at build time
VITE_API_URL=https://api.example.com npm run build

Fix 6: Syntax Error in Config

# ❌ Invalid config file
# ✅ Validate your config
node -e "require('./vite.config.js')"
node -e "require('./next.config.js')"

# Common issues:
# - Trailing commas in JSON
# - Missing module.exports
# - ESM vs CommonJS mismatch

Debugging

# Build with verbose output
npm run build -- --debug

# Check for circular dependencies
npx madge --circular src/

# Clear all caches
rm -rf node_modules/.cache .next/cache dist

Related resources

• Vite failed to resolve import fix
• Webpack module not found fix
• Vercel build failed fix
• Netlify build failed fix