Ruff extension can't find the pyproject.toml config when reading some files and not others

[Zeddicus414]

Hey all,

Thank you for maintaining the VSCode ruff extension. I love using ruff in my editor!

However, I've got a problem that I just can't figure out for the life of me...
The Ruff LSP throws 2025-03-06 16:02:55.146835200 WARN No settings available for file:///c%3A/Source/.../database_access.py - falling back to default settings for some files and not others in my project. Sometimes the files that work and don't work change. I'm not sure why.

My project has a pyproject.toml at the top level folder. If I run uv run ruff format . it works perfectly.

VSCode info:

Version: 1.98.0 (user setup)
Commit: 6609ac3d66f4eade5cf376d1cb76f13985724bcb
Date: 2025-03-04T21:06:18.612Z
Electron: 34.2.0
ElectronBuildId: 11044223
Chromium: 132.0.6834.196
Node.js: 20.18.2
V8: 13.2.152.36-electron.0
OS: Windows_NT x64 10.0.22631

Extension Installation:

Identifier charliermarsh.ruff
Version 2025.14.0
Last Updated 2025-02-28, 10:37:45
Size 35.65MB

Ruff settings:

  "[python]": {
    "editor.defaultFormatter": "charliermarsh.ruff",
    "editor.formatOnSave": true,
  },
  "ruff.configurationPreference": "filesystemFirst",
  "ruff.logFile": "c:/source/.../ruff.log",
  "ruff.logLevel": "debug",
  "ruff.importStrategy": "useBundled",

In the case of this log file, I literally have two files open in VSCode,

data_structures.py formats as I would expect and matches the CLI. etl_database_access.py formats with the default config and makes hundreds of changes.

I did change the project name in this log file, since it's work proprietary:
my_ruff.log

Any help or guidance would be greatly appreciated! Thank you so much for making something so cool and helpful for the python community.

[MichaReiser]

Thanks for the kind words and the detailed write up.

I believe the relevant lines in the log are:

2025-03-06 16:41:06.086695000 DEBUG Indexing settings for workspace: c:\source\PROJECTNAME
2025-03-06 16:41:06.098413500 DEBUG Ignored path via `exclude`: c:\source\PROJECTNAME\.git
2025-03-06 16:41:06.104849700 DEBUG Ignored path via `exclude`: c:\source\PROJECTNAME\.ruff_cache
2025-03-06 16:41:06.117166100  INFO Registering workspace: c:\source\PROJECTNAME
2025-03-06 16:41:06.177908300  WARN No settings available for file:///c%3A/Source/PROJECTNAME/etl/database/etl_database_access.py - falling back to default settings

Note how the workspace uses source in lowercase, whereas the warning message uses Source in uppercase. Can you tell me what the casing of C:\source is on disk? Is it C:\source or C:\Source? I'm not sure why VS code gives us once one path and than the other but I suspect that we may have to do some normalization on our end or change the setting lookup to be case-insensitive on case-insensitive file systems (windows, macos)

[dhruvmanila]

Another difference is that I think the path with lowercase source is a PathBuf while the one in uppercase Source is a Url. We do use the file path to get the settings: https://github.com/astral-sh/ruff/blob/d94a78a134c438c063d144e11f2ae8c1657dfa99/crates/ruff_server/src/session/index.rs#L211-L213.

[Zeddicus414]

The directory is uppercase C:\Source

Everything else in the path is lowercase, including the project name.