"There is no formatter for 'worktree-*' files installed"

[James_M (James)]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

If I open a worktree as the workspace root, formatting my document doesn’t work, it seems the detected language contains an erroneous “worktree-” prefix. The formatter works fine when I open the primary worktree as the root workspace. Both have the same settings.json config.

In my specific example, it’s a rust file, and my .vscode/settings.json uses:

"[rust]": {
    "editor.defaultFormatter": "rust-lang.rust-analyzer",
    "editor.formatOnSave": true,
    "editor.formatOnSaveMode": "file"
  },

And I have the rust-analyzer extension installed. But my auto-formatter doesn’t work and if I run the task for “Format Document” I get the attached modal error which shows that the language is being detected incorrectly.

Steps to Reproduce

1. Have cursor agent create a worktree
2. Open the ../.cursor/worktrees/*/*/ worktree in cursor so it’s the root workspace
3. Open a file whose type has a formatter config in .vscode/settings.json
4. Run “Format Document”

Expected Behavior

The document should be formatted when I run “Format Document”, since I have a formatter configured for this language.

Screenshots / Screen Recordings

Operating System

Linux

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.0.54
VSCode Version: 1.99.3
Commit: 7a31bffd467aa2d9adfda69076eb924e9062cb20
Date: 2025-11-03T22:40:44.657Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Linux x64 6.14.0-34-generic

For AI issues: which model did you use?

N/A

For AI issues: add Request ID with privacy disabled

N/A

Does this stop you from using Cursor

No - Cursor works, but with this issue