Package `prettier` can't be external

[coderrshyam]

Describe the Bug

Recently, I migrate to Biome from Prettier due to performance. After migration when i run my app using next dev I got error that Package prettier can't be external:

 ⚠ ./node_modules/.pnpm/@react-email+render@1.2.1_r_4cd7d00f12bf0fb695da21a0bfbc8367/node_modules/@react-email/render/dist/node
Package prettier can't be external
The request prettier/plugins/html matches serverExternalPackages (or the default list).
The request could not be resolved by Node.js from the project directory.
Packages that should be external need to be installed in the project directory, so they can be resolved from the output files.
Try to install it into the project directory by running npm install prettier from the project directory.

If user did not intrested in using prettier then why this type of warningis occured.

Which package is affected (leave empty if unsure)

react-email

Link to the code that reproduces this issue

https://github.com/resend/resend-nextjs-app-router-example

To Reproduce

1. Configure Next.js app.
2. Remove Prettier and integrate Biome.
3. Do some basic setup for react-email
4. Run the app, you see the issue.

Expected Behavior

There should be no error.

What's your node version? (if relevant)

22.18.0

[lveillard]

+1! Why is prettier in the normal dependencies? It's used for the templates?

[emiliosheinz]

@lveillard it’s currently used in the pretty function, which formats emails in a way that feels familiar to users. However, this is expected to be replaced soon by the work @gabrielmfern is doing in this PR, which should allow us to remove the dependency altogether.

[gabrielmfern]

Heads up, actually, we're most likely going to remove the pretty function and won't have #2361.

[emiliosheinz]

Thank you for clarifying @gabrielmfern :)