This is a tutorial on updating Github submodules the quick and easy way. This might be a bit hacky, but if you are like me and you just want to know how to update submodules without learning the ins and outs of Git, this is for you.

First things first, a submodule is a file in a Github repository that links to another repository. An example is aima-python, which links to aima-data. This is useful in organizing a project. You simply clone a repository and request that git downloads the contents of the other repository.

Notice how aima-python does not link to the master branch of aima-data though, instead linking to a particular branch created the moment the submodule is added. That means any changes to aima-data will be lost to the Python repository, since it will only download from the particular branch. So, once in a while you have to update the submodule.

I have found that this is easier said than done, and a Googling section doesn’t give much information. You have to be pretty knowledgable in git to do it, which seems like an overkill for such a simple task. Indeed, I have found a way to hack something together.

Basic Outline

You have to do the following things in this order:

  1. Clone the repository (it’s better to start clean, but it’s not necessary)
  2. Delete the current submodule
  3. Add the new submodule
  4. Push the commit

In More Detail

Clone your repository with the following:


Move into the repository’s directory:


Now for the deletion:

git submodule deinit SUBMODULE_NAME

To add the updated submodule:


Finally, commit and push. Here I push to the origin of the cloned repository, but you can do whatever you want. For example, this works for me:

git commit
git push origin