ContentLayer2 v0.5.8 causes a critical production build failure due to incompatibility with micromatch dependency

[issam-seghir]

The error occurs when contentlayer2 attempts to call micromatch.braces() which doesn't exist in the current micromatch API.

Details

Error Message:

TypeError: micromatch.braces is not a function
    at Object.<anonymous> (node_modules/contentlayer2/dist/core/index.js:xxx:xx)
    at Module._compile (node_modules/contentlayer2/dist/core/index.js)
    at Object.Module._extensions..js (module.js:xxx:xx)

Stack Trace:

Error occurred during Next.js production build
TypeError: micromatch.braces is not a function
    at contentlayer2/dist/core/index.js
    at webpack compilation
    at production build process

Environment

• ContentLayer2 Version: 0.5.8
• Next.js Version: 15.4.5
• Node.js Version: 22.17.0
• Package Manager: pnpm
• Environment: Production build (works in development)
• Platform: Coolify VPS Deployment**

Dependencies

{
  "contentlayer2": "^0.5.8",
   "next-contentlayer2": "^0.5.8",
  "next": "15.4.5",
}

Steps to Reproduce

Minimal Reproduction:

contentlayer.config.ts:

import { defineDocumentType, makeSource } from 'contentlayer2/source-files'

export const Post = defineDocumentType(() => ({
  name: 'Post',
  filePathPattern: `**/*.mdx`,
  contentType: 'mdx',
  fields: {
    title: { type: 'string', required: true },
  },
}))

export default makeSource({
  contentDirPath: './content',
  documentTypes: [Post],
})

next.config.mjs:

import { withContentlayer } from 'nextjs-contentlayer2'

/** @type {import('next').NextConfig} */
const nextConfig = {
  // basic config
}

export default withContentlayer(nextConfig)

Expected Behavior

ContentLayer2 should successfully compile during production builds without micromatch-related errors.

Actual Behavior

Production build fails with TypeError: micromatch.braces is not a function, preventing deployment.

Root Cause Analysis

The issue appears to be in contentlayer2's usage of the micromatch library. Based on investigation:

1. micromatch v4.x doesn't export a braces function directly
2. braces is a separate package (braces) that micromatch uses internally
3. ContentLayer2 is incorrectly trying to access micromatch.braces() instead of importing braces directly

Micromatch API (v4.x):

// ❌ INCORRECT (what contentlayer2 is doing)
import micromatch from 'micromatch'
micromatch.braces() // TypeError: not a function

// ✅ CORRECT (what should be done)
import braces from 'braces'
braces() // Works correctly