@next/mdx not compatible with --turbo

[goatyeahh]

Link to the code that reproduces this issue

https://github.com/goatyeahh/next-mdx-turbo-bug

To Reproduce

1. Start the app
2. Go to "/"

Current vs. Expected behavior

⨯ Error: Expected process result to be a module, but it was ignored

Debug info:

• Execution of get_written_endpoint_with_issues failed
• Execution of ::write_to_disk failed
• Execution of Project::emit_all_output_assets failed
• Execution of VersionedContentMap::insert_output_assets failed
• Execution of all_assets_from_entries failed
• Execution of AppEndpointOutput::output_assets failed
• Execution of AppEndpoint::output failed
• Execution of get_app_page_entry failed
• Execution of ::to_string failed
• Execution of AssetIdent::path failed
• Execution of Module::ident failed
• Execution of ProcessResult::module failed
• Expected process result to be a module, but it was ignored

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 23.2.0: Wed Nov 15 21:53:18 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T6000
  Available memory (MB): 32768
  Available CPU cores: 10
Binaries:
  Node: 20.13.1
  npm: 10.5.2
  Yarn: 1.22.19
  pnpm: 9.4.0
Relevant Packages:
  next: 14.2.4 // Latest available version is detected (14.2.4).
  eslint-config-next: 14.2.4
  react: 18.3.1
  react-dom: 18.3.1
  typescript: 5.5.3
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

No response