Dev server exits early in Next15 when using Turbopack

[MangoMarcus]

Link to the code that reproduces this issue

https://github.com/MangoMarcus/turbopack-exit

To Reproduce

• Install with npm i
• Run development server with npm run dev
• Open http://localhost:3000 in your browser
• npm run dev will exit with code 0, without an error.

Current vs. Expected behavior

npm run dev will exit with code 0, without an error

Provide environment information

Operating System:
  Platform: macOS
  Chip: Apple M1 Pro
  Version: macOS 14.4
Binaries:
  Node: 20.2.0
  npm: 9.6.6
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 15.0.3
  eslint-config-next: 15.0.3
  react: react@19.0.0-rc-66855b96-20241106
  react-dom: 19.0.0-rc-66855b96-20241106
  typescript: 5.6.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Turbopack

Which stage(s) are affected? (Select all that apply)

next dev (local)

Additional context

This was not an issue before migrating to Next 15 and also only affects Turbopack, not Webpack. I've narrowed down the issue to Preline, although I'm not sure if the underlying issue is with Next, Turbopack, or Preline. As it works fine on either Next 14 or Webpack, I'm guessing it's not Preline itself that's the issue.

I've added some 'XXX' comments for context, it seems the process exits whenever a Preline import is read, eg. console.log(typeof Preline)

[samcx]

@MangoMarcus I'm not sure you're even supposed to import Preline outside of <PrelineScript /> in the Layout.

I tried setting up with the documentation (they have a StackBlitz example), and it seem to work!

[MangoMarcus]

@samcx The problem isn't in importing the preline scripts (eg. import("preline/preline"), like in their NextJS example), it's with importing the Preline Tailwind plugin (eg. `import PrelinePlugin from 'preline/plugin'). That's what my repo shows - it only adds Preline as a Tailwind plugin, it doesn't actually use any of its components or initialise its scripts or styles.

Normally you wouldn't do this outside of the Tailwind config file, but as mentioned in my reproduction my use case is a module where I import the Tailwind config with `import tailwindConfig from '@/../tailwind.config' in order to reuse the config in other modules - eg. screen sizes. As mentioned in the repo comments it only happens when the plugin import is read - eg. console.log(typeof PrelinePlugin) is enough to cause the dev server to exit.

Regardless of how conventional this setup is it works fine with Webpack in Next 14 and 15, or with Turbopack in Next 14, but exits without an error with Turbopack in Next 15, doesn't that constitute a bug that needs addressing? Shouldn't it never exit without an error? I'm currently unable to use Webpack due to a different issue.

It took a long time to narrow down the bug this far so I'd appreciate it being investigated ty 🙏