Branches

Introduction

Branches are named pointers to revisions (just like they are in Git). You can move them without affecting the target revision's identity. Branches automatically move when revisions are rewritten (e.g. by jj rebase). You can pass a branch's name to commands that want a revision as argument. For example, jj co main will check out the revision pointed to by the "main" branch. Use jj branch list to list branches and jj branch to create, move, or delete branches. There is currently no concept of an active/current/checked-out branch.

Remotes

Jujutsu identifies a branch by its name across remotes (this is unlike Git and more like Mercurial's "bookmarks"). For example, a branch called "main" in your local repo is considered the same branch as a branch by the same name on a remote. When you pull from a remote (currently only via jj git fetch), any branches from the remote will be imported as branches in your local repo.

Jujutsu also records the last seen position on each remote (just like Git's remote-tracking branches). You can refer to these with <branch name>@<remote name>, such as jj new main@origin. Most commands don't show the remote branch if it has the same target as the local branch. The local branch (without @<remote name>) is considered the branch's desired target. Consequently, if you want to update a branch on a remote, you first update the branch locally and then push the update to the remote. If a local branch also exists on some remote but points to a different target there, jj log will show the branch name with an asterisk suffix (e.g. main*). That is meant to remind you that you may want to push the branch to some remote.

When you pull from a remote, any changes compared to the current record of the remote's state will be propagated to the local branch. Let's say you run jj git fetch --remote origin and the remote's "main" branch has moved so its target is now ahead of the local record in main@origin. That will update main@origin to the new target. It will also apply the change to the local branch main. If the local target had also moved compared to main@origin (probably because you had run jj branch set main), then the two updates will be merged. If one is ahead of the other, then that target will be the new target. Otherwise, the local branch will be conflicted (see next section for details).

Conflicts

Branches can end up in a conflicted state. When that happens, jj status will include information about the conflicted branches (and instructions for how to mitigate it). jj branch list will have details. jj log will show the branch name with a question mark suffix (e.g. main?) on each of the conflicted branch's potential target revisions. Using the branch name to look up a revision will resolve to all potential targets. That means that jj co main will error out, complaining that the revset resolved to multiple revisions.

Both local branches (e.g. main) and the remote branch (e.g. main@origin) can have conflicts. Both can end up in that state if concurrent operations were run in the repo. The local branch more typically becomes conflicted because it was updated both locally and on a remote.

To resolve a conflicted state in a local branch (e.g. main), you can move the branch to the desired target with jj branch. You may want to first either merge the conflicted targets with jj merge, or you may want to rebase one side on top of the other with jj rebase.

To resolve a conflicted state in a remote branch (e.g. main@origin), simply pull from the remote (e.g. jj git fetch). The conflict resolution will also propagate to the local branch (which was presumably also conflicted).