nextjs - 💡(How to fix) Fix Next.js 16.2.x build crash (SIGTRAP) with Pages Router + i18n + next/font + standalone

Link to the code that reproduces this issue

Private repo (bhaptics.com). Reproduction steps below.

To Reproduce

1. Next.js project with Pages Router
2. Configuration:
   • i18n with 7 locales (en, ko, ja, zh, es, fr, de)
   • output: "standalone"
   • trailingSlash: true
   • next/font (Noto Sans) imported in _app.tsx
   • middleware.ts with locale redirect logic
   • ~350 pages
3. Upgrade from Next.js 16.1.7 to 16.2.5 or 16.2.6
4. Run next build (Turbopack) or next build --webpack

Current vs. Expected behavior

Current: Build crashes immediately after "Creating an optimized production build..."

▲ Next.js 16.2.6 (webpack)
⚠ The "middleware" file convention is deprecated. Please use "proxy" instead.
✓ Finished TypeScript in 16.1s
  Creating an optimized production build ...
Next.js build worker exited with code: null and signal: SIGTRAP

Expected: Build completes successfully (works fine on 16.1.7).

What I've tried

• next build (Turbopack default) → SIGTRAP
• next build --webpack → SIGTRAP
• .babelrc with next/babel preset → SWC disabled but fails because next/font requires SWC
• NODE_OPTIONS="--max-old-space-size=8192" → same crash
• NEXT_DEBUG_BUILD=1 → no additional debug output
• Clean install (rm -rf node_modules .next && npm install) → same crash
• Node.js 20.13.1 and 22.x → same crash on both
• Next.js 16.2.5 and 16.2.6 → same crash on both
• macOS ARM64 (Apple Silicon) and Linux (GCP Cloud Build) → same crash on both platforms

Environment

• Next.js: 16.2.5 / 16.2.6 (works on 16.1.7)
• React: 19.2.6
• Node.js: 20.13.1 / 22.x
• OS: macOS ARM64 (M-series) + Linux x64 (GCP)
• Package manager: npm
• Pages Router with next-i18next

Which area(s) are affected?

SWC, Build (next build), Pages Router

Additional context

• SWC native binary (@next/swc-darwin-arm64) is correctly installed and matches the platform
• The crash happens in the SWC compilation phase (after TypeScript check, during "optimized production build")
• Since --webpack flag only changes the bundler but still uses SWC for transpilation, the crash persists
• This is a security-critical blocker: 16.2.5+ contains patches for 12 CVEs (middleware bypass, SSRF, XSS, DoS) per https://developers.cloudflare.com/changelog/post/2026-05-06-react-nextjs-vulnerabilities/