How to fix fatal: 'feature' is already checked out at '/path/to/worktree' in Git

First, see what worktrees Git knows about and which branches they have checked out:

git worktree list

This will show output like:

/home/user/project        abc1234 [main]
/home/user/project-feature def5678 [feature]

Check if the branch mentioned in the error is actually in use by one of these worktrees, or if the listed path no longer exists on disk.

If a worktree directory was deleted manually (not using git worktree remove), Git still thinks it exists. Prune these stale references:

# See what would be pruned without actually doing it
git worktree prune --dry-run

# Actually prune stale worktree information
git worktree prune

After pruning, try your checkout or worktree add command again. This fixes the error in most cases where the worktree was manually deleted.

If the worktree still exists and you no longer need it, remove it properly:

# Remove the worktree (safer than manual deletion)
git worktree remove /path/to/worktree

# Force remove if there are untracked files or modifications
git worktree remove --force /path/to/worktree

This removes both the directory and Git's internal reference to the worktree.

If you intentionally want the same branch checked out in multiple worktrees (understanding the risks), use the --force flag:

# Force checkout even if branch is used elsewhere
git worktree add --force /path/to/new/worktree feature

# Force also works with git checkout in some scenarios
git checkout --force feature

Warning: Having the same branch in multiple worktrees can cause confusion. If you commit in one worktree, the other will have an outdated branch reference and may show unexpected behavior.

If you just need to view or test code at the same commit as the branch, use a detached HEAD:

# Create worktree with detached HEAD at the same commit
git worktree add --detach /path/to/new/worktree feature

# Or checkout in detached HEAD mode
git checkout --detach feature

With detached HEAD, you're at the same commit but not on the branch, so there's no conflict. Any commits you make will need to be explicitly saved to a branch.

Create a new branch pointing to the same commit as the one you can't check out:

# Create a new branch at the same point as 'feature'
git worktree add -b feature-worktree2 /path/to/new/worktree feature

This creates a new worktree with a branch called feature-worktree2 that starts at the same commit as feature. You can work independently and merge or cherry-pick changes later.

In Git 2.43+, a branch can be "in use" if it's in the middle of a rebase or bisect in another worktree:

# Check for rebase or bisect state in worktrees
ls .git/worktrees/*/rebase-merge 2>/dev/null
ls .git/worktrees/*/BISECT_LOG 2>/dev/null

If found, go to that worktree and complete or abort the operation:

# Abort rebase in the other worktree
git -C /path/to/other/worktree rebase --abort

# Or abort bisect
git -C /path/to/other/worktree bisect reset

If nothing else works, you can manually remove Git's worktree tracking data:

# List worktree metadata directories
ls .git/worktrees/

# Remove the stale worktree reference (be careful!)
rm -rf .git/worktrees/worktree-name

Warning: Only do this if you're certain the worktree no longer exists on disk. This directly modifies Git's internal state.