[StackOverflow/docker] How to checkout a branch when all branches are already checked out at '<current_working_tree>'

### ROOT CAUSE The issue arises because Git does not allow multiple branches to be checked out simultaneously in the same working tree. The error occurs when attempting to checkout a branch while already in a state where multiple branches are checked out (e.g., using `git worktree` or detached HEAD). The command `git checkout` expects a branch name, but the system detects the current working tree is already checked out for all branches, causing ambiguity. ### CODE FIX To resolve this, explicitly specify the branch name or ensure you are not in a detached HEAD state. Use one of the following solutions: 1. **Checkout a specific branch**: ```bash git checkout ``` 2. **Create a new branch and checkout** (if the branch doesn’t exist): ```bash git checkout -b ``` 3. **Switch to a worktree** (if using `git worktree`): ```bash git worktree switch -f ``` 4. **Ensure no detached HEAD**: ```bash git checkout ``` **Note**: Replace `` with your target branch. If the branch doesn’t exist, create it first using `git checkout -b`. This ensures Git knows exactly which branch to checkout.