Start a new git worktree from an existing branch other than the default

worktree.md

Starting out

Run these commands in a directory devoted to your project:

mkdir project_foo
cd project_foo
git clone --bare [email protected]:yourorg/project_foo.git .bare
echo "gitdir: ./.bare" > .git

Now edit .bare/config, adding fetch = +refs/heads/*:refs/remotes/origin/* below [remote "origin"]

[remote "origin"]                               
  url = [email protected]:yourorg/project_foo.git 
  fetch = +refs/heads/*:refs/remotes/origin/*  

Branches

To create a branch and a worktree) that is based off of main:

1. Go to the main worktree.
2. git pull origin main
3. cd .. #get out of the main worktree and branch
4. git worktree add ./my-new-branch #creates a my-new-branch directory, as well as a branch of the same name

To create a worktree based off of an existing branch present in the local repository

1. Go the worktree root of the repository (where the .bare directory is located)
2. git worktree add ./existing-branch-name existing-branch-name

That last command should show you the following (if the local branch is setup to track a remote origin):

Preparing worktree (new branch 'existing-branch-name')                                       
branch 'existing-branch-name' set up to track 'origin/existing-branch-name'.       
HEAD is now at cf5bfce6b creating the foobaz                                                                  

If the local branch isn't tracking the remote branch of the same name, do the following:

cd existing-branch-name  
git branch --set-upstream-to=origin/existing-branch-name  

In response, you should see the following:

branch 'existing-branch-name' set up to track 'origin/existing-branch-name'

Run git status to confirm this.

Hints

It might be helpful to first push a locally created branch to the remote and then create a worktree based on that remote rather than attempt to create a worktree on a locally created branch that's not tracking a remote branch.

To add a worktree that's based on a branch other than the default (usually main) and tracks that existing, remote branch: git fetch --all --prune git worktree add --track -b new_worktree_branch ./new_worktree_path remote_name/existing_branch

To add a worktree that exists on a remote but has a slash in the branch name: git fetch --all --prune git worktree add --guess-remote local-dir-name "branch/name-with-slash"

To add a worktree whose branch exists on the remote only:

[2023-06-01 14:51:38]>> git fetch origin dockerfile-updates
From github.com:yourorg/project_foo
 * branch              dockerfile-updates -> FETCH_HEAD
[ main][🅰 ][project_foo]
[2023-06-01 14:52:00]>> git worktree add ./dockerfile-updates FETCH_HEAD 

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*Source: https://infrequently.org/2021/07/worktrees-step-by-step/