bug: installation fails on biome formatting

[FilipMasar]

Provide environment information

  System:
    OS: macOS 15.7.2
    CPU: (8) arm64 Apple M1 Pro
    Memory: 1.06 GB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 24.12.0 - /Users/filip/.nvm/versions/node/v24.12.0/bin/node
    Yarn: 1.22.21 - /opt/homebrew/bin/yarn
    npm: 11.6.2 - /Users/filip/.nvm/versions/node/v24.12.0/bin/npm
    pnpm: 10.14.0 - /Users/filip/Library/pnpm/pnpm
    Watchman: 2025.03.10.00 - /opt/homebrew/bin/watchman

Describe the bug

Biome formatting fails right during the installation (eslint, prettier setup works). Here are the options I picked

pnpm create t3-app@latest

   ___ ___ ___   __ _____ ___   _____ ____    __   ___ ___
  / __| _ \ __| /  \_   _| __| |_   _|__ /   /  \ | _ \ _ \
 | (__|   / _| / /\ \| | | _|    | |  |_ \  / /\ \|  _/  _/
  \___|_|_\___|_/‾‾\_\_| |___|   |_| |___/ /_/‾‾\_\_| |_|


│
◇  What will your project be called?
│  bookni3
│
◇  Will you be using TypeScript or JavaScript?
│  TypeScript
│
◇  Will you be using Tailwind CSS for styling?
│  Yes
│
◇  Would you like to use tRPC?
│  Yes
│
◇  What authentication provider would you like to use?
│  NextAuth.js
│
◇  What database ORM would you like to use?
│  Prisma
│
◇  Would you like to use Next.js App Router?
│  Yes
│
◇  What database provider would you like to use?
│  PostgreSQL
│
◇  Would you like to use ESLint and Prettier or Biome for linting and formatting?
│  Biome
│
◇  Should we initialize a Git repository and stage the changes?
│  Yes
│
◇  Should we run 'pnpm install' for you?
│  Yes
│
◇  What import alias would you like to use?
│  ~/

Using: pnpm

Reproduction repo

https://github.com/FilipMasar/t3-reproducable-bug

To reproduce

This is an untouched code that was generated from installation script until it fails.
You can just run pnpm run check:unsafe to see the error

Additional information

It can be fixed by putting generated/prisma/ into .gitignore. Not sure why it is not there. Also not sure why it was chosen to specify prisma output and not just use default (node_modules) output

Here is an example of errors

Aborting installation...
Error: Command failed with exit code 1: pnpm run check:unsafe
generated/prisma/runtime/index-browser.d.ts:9:27 lint/suspicious/noExplicitAny ━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected any. Specify a different type.
  
     7 │             operations: {
     8 │                 [K in F]: {
   > 9 │                     args: any;
       │                           ^^^
    10 │                 };
    11 │             };
  
  i any disables many type checking rules. Its use should be avoided.
  

generated/prisma/runtime/index-browser.d.ts:14:51 lint/suspicious/noExplicitAny ━━━━━━━━━━━━━━━━━━━━

  ! Unexpected any. Specify a different type.
  
    12 │         };
    13 │     };
  > 14 │ } ? T[symbol]['types']['operations'][F]['args'] : any;
       │                                                   ^^^
    15 │ 
    16 │ declare class DbNull extends NullTypesEnumValue {
  
  i any disables many type checking rules. Its use should be avoided.

[hallowatcher]

I have the same issue.

Adding this to the biome.jsonc file fixes the check:unsafe command:

{
  ...,
  "files": {
    "includes": ["**", "!generated"]
  },
}

It will still complain about the button elements in page.tsx not having a type="button".

It's sad because this was my first time using the t3 stack, not a good look :/

[gitnlsn]

i report the same issue. I had to downgrad to 7.38 version install.

[YakovL]

@FilipMasar why this is marked as unconfirmed? I have this issue (among others), too (and like for hallowatcher, there are also a couple of issues at src\app\page.tsx:60:10 and src\app\page.tsx:81:10, complains about missing type).

Not if extending one of biome's config and .gitignore is more proper than the other, but probably .gitignore is (because git also tracks those files); this looks related: biomejs/biome#8139 (and/or prisma/prisma#28540).