What this error means

Turbopack production build: e.indexOf is not a function → TypeError: Cannot read properties of undefined (reading 'toUrl') when Web Worker created via new URL(..., import.meta.url) is a Vercel failure pattern reported for developers trying to fix regression in next.js 16.2 turbopack where web worker instantiation via import.meta.url crashes in production, breaking language-service workers. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue vercel/next.js#94015 — confirmed regression in Turbopack 16.2. Production builds crash with Worker creation errors. GraphiQL Monaco editor completely broken. Reproducible via minimal reproduction repo. Affects Vercel-hosted Next.js deployments with dependency on Monaco or similar Worker-based editors.

Common causes

  • GitHub issue vercel/next.js#94015 — confirmed regression in Turbopack 16.2. Production builds crash with Worker creation errors. GraphiQL Monaco editor completely broken. Reproducible via minimal reproduction repo. Affects Vercel-hosted Next.js deployments with dependency on Monaco or similar Worker-based editors.

Quick fixes

  1. Confirm the exact error signature matches Turbopack production build: e.indexOf is not a function → TypeError: Cannot read properties of undefined (reading 'toUrl') when Web Worker created via new URL(..., import.meta.url).
  2. Check the Vercel account, local tool state, and provider configuration involved in the failing workflow.
  3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

  • Verify the command, editor, extension, or API client that produced the error.
  • Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
  • Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

  1. Capture the exact error message and the command, editor action, or request that triggered it.
  2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
  3. Review the source evidence below and compare it with your environment.
  4. Apply one change at a time and rerun the smallest failing action.
  5. Keep the working fix documented for the team or deployment environment.

How to prevent it

  • Keep provider/tool configuration documented.
  • Record non-secret diagnostics such as tool version, provider name, model name, and command path.
  • Add a lightweight check before CI or production workflows depend on the tool.