Published on July 02, 2012
git checkout has an
--orphan option that will create a branch with no “parents” or relation at all to other branches/commits in the repository.
From the man page:
Create a new orphan branch, named <new_branch>, started from <start_point> and switch to it. The first commit made on this new branch will have no parents and it will be the root of a new history totally disconnected from all the other branches and commits.
The index and the working tree are adjusted as if you had previously run
git checkout <start_point>. This allows you to start a new history that records a set of paths similar to <start_point> by easily running
git commit -ato make the root commit.
This can be useful when you want to publish the tree from a commit without exposing its full history. You might want to do this to publish an open source branch of a project whose current tree is “clean”, but whose full history contains proprietary or otherwise encumbered bits of code.
If you want to start a disconnected history that records a set of paths that is totally different from the one of <start_point>, then you should clear the index and the working tree right after creating the orphan branch by running
git rm -rf .from the top level of the working tree. Afterwards you will be ready to prepare your new files, repopulating the working tree, by copying them from elsewhere, extracting a tarball, etc.
When I shared this “feature” with a few colleagues, one response I received was:
“bizarre – why would you want that?”
A few possibilities:
Obviously there are other ways to handle all of these possibilities; for instance, hosting documentation in a GitHub Wiki, or pushing resources for bootstrapping, testing, and deployment into various
git-submodules that are initialized/updated only if necessary.
Regardless of the use-case, something to keep in mind when using an orphan branch: Communicate clearly to others who may interact with the repository what the branch is and how to work with it; blindly stumbling across an orphan branch could be pretty confusing.