Fix Next.js 16 Compile Stuck on Turbopack Dev Server

Iwan Efendi•last monthMar 8, 2026•3 min

How I debugged and fixed the Next.js 16 Turbopack dev server that kept crashing at 'Compiling /[locale]' after migrating to Tailwind CSS v4.

The Symptom
The Wrong Turns
Attempt 1: Restarting the Server
Attempt 2: Checking Port Conflicts
Attempt 3: Reverting Git Commits
Finding the Root Cause
The Permanent Fix
Why This Happened
Key Takeaways

After successfully migrating SnipGeek from Tailwind CSS v3.4.1 to v4 and Next.js 15 to 16, I hit a frustrating wall: the dev server kept dying silently at ○ Compiling /[locale] ... with exit code 1. No error message. No stack trace. Just... dead. This note documents the full debugging journey—every wrong turn and the final fix—so you don't have to waste hours on the same problem.

The Symptom

Every time I ran npm run dev, the Turbopack server would start fine:

▲ Next.js 16.1.6 (Turbopack)
- Local: http://localhost:9003

✓ Starting...
✓ Ready in 1552ms
○ Compiling /[locale] ...
# ← process dies here, exit code 1

No compilation error. No helpful log. The process simply vanished.

The Wrong Turns

Before finding the root cause, I went through several failed attempts that are worth documenting.

Attempt 1: Restarting the Server

The most obvious first step. Kill the process, restart. Same result every time—stuck at the same point.

Attempt 2: Checking Port Conflicts

I suspected port 9003 was already in use:

netstat -ano | findstr :9003

Sometimes it was, sometimes it wasn't. Killing the orphan process and restarting didn't help. The server would start, then crash again at compilation.

Attempt 3: Reverting Git Commits

I even rolled back to an older commit (c640944 — the pre-migration backup) to rule out code changes. The older Tailwind v3 codebase had its own issues with the newer dependencies, so this wasn't a viable path either.

Don't Panic-Revert

Rolling back multiple commits without understanding the root cause can create more problems than it solves. Always diagnose first.

Finding the Root Cause

The breakthrough came when I took a more systematic approach:

Cleared the .next cache completely.

Remove-Item -Recurse -Force .next

Stale Turbopack cache from the migration could have been causing compilation to choke.

Increased Node.js memory allocation.The /[locale] route in SnipGeek is heavy—it imports Firebase, Radix UI, Framer Motion, Recharts, and many other dependencies. The default Node.js heap size (~1.7 GB) was not enough for Turbopack to compile everything.

$env:NODE_OPTIONS="--max-old-space-size=4096"
npx next dev --turbopack -p 9003

Fixed the proxy export name.Next.js 16 renamed middleware to proxy. The file was already renamed to src/proxy.ts, but the exported function was still called middleware:

// ❌ Before (crashes silently)
export function middleware(request: NextRequest) { ... }

// ✅ After
export function proxy(request: NextRequest) { ... }

After all three fixes, the server compiled successfully:

✓ Ready in 2.3s
○ Compiling /[locale] ...
 GET / 200 in 9.2s (compile: 7.8s, proxy.ts: 82ms, render: 1249ms)

The compilation took 7.8 seconds—which is why it appeared to be stuck. It was actually working, but running out of memory before it could finish.

The Permanent Fix

I updated the dev script in package.json to always allocate sufficient memory:

{
  "scripts": {
    "dev": "cross-env NODE_OPTIONS=--max-old-space-size=4096 next dev --turbopack -p 9003"
  }
}

Why This Happened

Three factors combined to create the silent crash:

Factor	Detail
Turbopack + large route	The `/[locale]` layout imports 15+ heavy packages (Firebase, Radix UI, Framer Motion, etc.)
Default memory limit	Node.js defaults to ~1.7 GB heap, insufficient for bundling all dependencies
Silent OOM	Turbopack doesn't surface out-of-memory errors clearly—the process just exits with code 1

Quick Diagnostic

If your Next.js 16 dev server dies silently during compilation, the first thing to try is increasing memory: NODE_OPTIONS=--max-old-space-size=4096. This alone solves many Turbopack compilation crashes.

Key Takeaways

Silent exit code 1 during Turbopack compilation is often an OOM issue. Always check memory allocation first.
Clear .next cache after major migrations. Stale cache can cause unpredictable compilation failures.
Next.js 16 requires proxy export, not middleware. The error message for this is clear, but it can get buried if other issues crash the server first.
Don't panic-revert. Diagnose systematically before rolling back commits.

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