vercel/next.js · error

Prerendering is running in debug mode with NODE_ENV='develop

Error message

Prerendering is running in debug mode with NODE_ENV='development'. This will affect performance and should not be used for production.

What it means

Warning printed by next-build when the --debug-prerender flag is used. It indicates the build compiles prerendering code in development mode (NODE_ENV=development) to yield richer debugging output for hydration or prerender failures. This makes the output unsuitable for deployment: the resulting build is slower and lacks production optimizations, and is meant only for diagnosing prerender errors.

Source

Thrown at packages/next/src/cli/next-build.ts:86

    printAndExit(
      '--experimental-analyze is only compatible with the Turbopack bundler.'
    )
  }

  if (!mangling) {
    warn(
      `Mangling is disabled. ${italic('Note: This may affect performance and should only be used for debugging purposes.')}`
    )
  }

  if (profile) {
    warn(
      `Profiling is enabled. ${italic('Note: This may affect performance.')}`
    )
  }

  if (debugPrerender) {
    warn(
      `Prerendering is running in debug mode with NODE_ENV='development'. ${italic(
        'This will affect performance and should not be used for production.'
      )}`
    )
  }

  if (experimentalDebugMemoryUsage) {
    process.env.EXPERIMENTAL_DEBUG_MEMORY_USAGE = '1'
    enableMemoryDebuggingMode()
  }

  const dir = getProjectDir(directory)

  if (!existsSync(dir)) {
    printAndExit(`> No such directory exists as the project root: ${dir}`)
  }

  let debugBuildPathsPatterns: string[] | undefined

View on GitHub (pinned to 0eb3775416)

Solutions

1. Do not use debug prerender mode for production builds; run `next build` normally for production output.

When it happens

Trigger: Thrown at packages/next/src/cli/next-build.ts:86 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of vercel/next.js@0eb3775416 (2026-08-19). Data as JSON: /api/errors/b9cd0d518afa8d4d. Report an issue: GitHub.