Branch picker includes linked-worktree '+' marker in git checkout

[denysbutenko]

Pre-submit Checks

• I have searched Warp bugs and there are no duplicates.
• I have searched Warp known issues page and my issue is not there.

Describe the bug

When selecting a branch from Warp's branch picker/search UI, if that branch is checked out in another linked git worktree, Warp appears to include Git's leading + marker in the checkout command.

For example, the branch is shown as:

+ 273-improvement-suggestion-agent

Warp then appears to execute:

git checkout + 273-improvement-suggestion-agent

which fails with:

error: pathspec '+' did not match any file(s) known to git
error: pathspec '273-improvement-suggestion-agent' did not match any file(s) known to git

This looks like Warp is parsing raw git branch display output and treating the leading + linked-worktree marker as part of the checkout arguments.

To reproduce

1. Create a repository with linked git worktrees.
2. Check out a branch in another worktree.
3. In Warp, open the branch picker/search UI from a different worktree of the same repo.
4. Select the branch that is shown with a leading +.
5. Warp attempts checkout and the command fails.

Expected behavior

Warp should not pass the leading + marker to git checkout.

It should either:

• strip the marker and use only the real branch name, or
• prevent checkout with a clear message that the branch is already checked out in another linked worktree.

Screenshots, videos, and logs

I have screenshots showing:

• the branch picker showing + 273-improvement-suggestion-agent
• the resulting error after Warp attempts checkout:

error: pathspec '+' did not match any file(s) known to git
error: pathspec '273-improvement-suggestion-agent' did not match any file(s) known to git

Operating system (OS)

macOS

Operating system and version

26.3.1

Shell Version

zsh 5.9 (arm64-apple-darwin25.0)

Current Warp version

v0.2026.04.15.08.45.stable_02

Regression

Unknown

Recent working Warp date

No response

Additional context

This repository uses linked git worktrees.

Local git branch --list output includes:

+ 263-catalog-page-allow-sorting
+ 269-adapt-ui-dataset-subset
+ 271-move-super-admin
+ 273-improvement-suggestion-agent
+ 274-static-config
+ 284-handle

The + is Git's marker for a branch checked out in another linked worktree, not part of the branch name.