2.0.0-beta.1: lint in subdirectory not using root .gitignore

[ValentinGurkov]

Environment information

CLI:
  Version:                      2.0.0-beta.1
  Color support:                true

Platform:
  CPU Architecture:             x86_64
  OS:                           windows

Environment:
  BIOME_LOG_PATH:               unset
  BIOME_LOG_PREFIX_NAME:        unset
  BIOME_CONFIG_PATH:            unset
  NO_COLOR:                     unset
  TERM:                         xterm-256color
  JS_RUNTIME_VERSION:           v22.14.0
  JS_RUNTIME_NAME:              node
  NODE_PACKAGE_MANAGER:         pnpm/10.6.5

Biome Configuration:
  Status:                       Loaded successfully
  Path:                         <redacted>\biome.jsonc
  Formatter enabled:            true
  Linter enabled:               true
  Assist enabled:               true
  VCS enabled:                  true

Workspace:
  Open Documents:               0

What happened?

Running biome check for a subdirectory/package in a monorepo does not use the .gitingore file from the project root. I noticed the command taking forever and figured it was due to it formatting my Next.js output folder .next.
I created a .gitignore for the subdirectory and the process took 109ms.

The output folder is ignored this way in the root .gitignore:

.next

Expected result

While I am not 100% everyone would consider this a bug, ESLint in a monorepo scenario can work with a single .gitingore file at the project root, so I expected the same here.

Version 1.9.4 also uses the root .gitignore correctly.

Reproduction

https://github.com/ValentinGurkov/biome-repro-1742925348856

Code of Conduct

• I agree to follow Biome's Code of Conduct

[ematipico]

Yeah, this isn't a bug. Full monorepo support hasn't been completed yet: #2228

[ValentinGurkov]

I just tested this with 1.9.4 and it used the root .gitignore, so this version might be more favorable for the time being. I want to thank you for all your effort towards supporting monorepos, I imagine how complicated things can get!

[ematipico]

@ValentinGurkov can you please provide a reproduction?

[github-actions]

Hello @ValentinGurkov, please provide a minimal reproduction. You can use one of the following options:

• Provide a link to our playground, if it's applicable.
• Provide a link to GitHub repository. To easily create a reproduction, you can use our interactive CLI via npm create @biomejs/biome-reproduction

Issues marked with S-Needs repro will be closed if they have no activity within 3 days.

[depsimon]

Yeah, this isn't a bug. Full monorepo support hasn't been completed yet: #2228

Any workaround that could work with the beta version?

[ematipico]

Yeah, this isn't a bug. Full monorepo support hasn't been completed yet: #2228

Any workaround that could work with the beta version?

Use a top-level command to lint the whole monorepo.

[ValentinGurkov]

I have managed to create a minimal reproduction that can be found at https://github.com/ValentinGurkov/biome-repro-1742925348856.

I have enabled one correctness rule noUnusedVariables. The default rules configuration did not reproduce this.

How to reproduce with the repository:

1. On the master branch run:

pnpm i
cd packages/package-a/
pnpm build
pnpm check

The report should only include errors for src/index.ts.

2. Then checkout the branch 2.0.0-beta.1.
   Run (without switching folders):

pnpm i
pnpm check

The diagnostics also report errors for build/src/index.js related to the rule noUnusedVariables.

This regression could be related to how the .gitignore file is handled, the rule noUnusedVariables, or the new multi-file analysis feature, I am only guessing.

Оr it could be that setup (root config and ignore file but package-specific command) worked by sheer chance on older versions and was never intended.

I hope I managed to be of some help, this is my first time opening an issue here.

[ematipico]

I checked your reproduction, and it's possible that it worked by chance. It has a monorepo setting, which isn't supported at the moment. See #2228

As a workaround, lint the entire project from the root, and use overrides to tweak rules/etc. based on the project. Biome is fast, it shouldn't make too much of a difference.