[BUG] Code tab: "Start with worktree" always fails for repos on a network share (UNC path) — regression since ~Sept 2026

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In the Desktop app's Code tab, "Start with worktree" on a suggested task chip always fails with only the toast "Couldn't start the suggested task." when the repository lives on a network share (UNC path, e.g. \\NAS\share\Project). "Start locally" works.

This worked until early September 2026 (last successful worktree session in my logs: 2026-09-07; first failure: 2026-09-16; every attempt since fails).

The repo is a plain folder: .git and .claude are real directories (not symlinks/junctions), no git remote. Git itself handles the share fine: git worktree add -b test C:\somewhere master from the same UNC repo succeeds (safe.directory is configured).

Possibly related: #94610 (same generic toast with no surfaced error, but on macOS).

What Should Happen?

The worktree session should start (as it did until early September), or at least the toast should show the real reason. Ideally an opt-in setting allows worktrees for repos on a trusted network share.

Error Messages/Logs

Worktree location = "Inside project":
[createWorktree] no repository anchor for \\NAS\share\Project (not a git repository)
Refusing worktree creation for \\NAS\share\Project: .claude could not be verified as a real folder
Worktree creation failed with error: worktree_store_symlinked, aborting session

Worktree location = custom local folder (C:\ClaudeWorktrees):
[worktreeOverlay] git ls-files failed (git_error): git.exe exited with code 128: fatal: not a git repository: '\\.\NUL'
[createWorktree] \\NAS\share\Project/.git could not be walked (refused); not creating a worktree through it
Worktree creation failed with error: worktree_backlink_broken
"Claude Desktop could not create a worktree: <unc>\Project\.git could not be read, or leads through a link into a network location this app will not follow."

Steps to Reproduce

1. Put a git repo on an SMB network share and open it in the Code tab via its UNC path.
2. Let Claude suggest a task (spawn_task chip).
3. Click "Start with worktree" -> toast "Couldn't start the suggested task."
4. Check %LOCALAPPDATA%\Claude\logs\main.log for the lines above.
5. Changing Settings -> Claude Code -> Worktree location to a local folder only moves the failure to the next check.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Unknown – worked on 2026-09-07

Claude Code Version

2.1.286 (Claude Desktop 2.19675.0)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_