No Submodule Found In .gitmodule

What is a git submodule and where did it come from?

I recently worked on a project that had multiple independent programs that I needed to write.

These were committed to a git repo.

One of the programs was an API library, for which I decided to create a separate repo with a different name, as it had other use cases for me.

When I pushed the umbrella project to Github, lo and behold, I see this:

-Subproject commit 1515a6f60156cb658036ba6008759fd9509fc17f

That is, I only see this commit id, and there’s no code. From multiple files to this awesome one-liner.

This is by design in Git, so that you can “clone another repository into your project and keep your commits separate.

A submodule is effectively a reference to a separate Git project via a particular commit. (I didn’t find a clear definition in the docs)

However, for my project, I needed the code not a commit number! Where is it?

It is still in the other git repo, completely separate.

Per the docs and StackOverflow, I tried this to fix it:

git submodule update --init

To no avail. This gave me the error:

No submodule mapping found in .gitmodules

I do not know why the submodule reference would not be in the .gitmodules. Whatever the reason, this did not work.

What I needed to do is delete the cache (which I also found on StackOverflow here):

git rm --cached path/to/gitrepo

(By the way, I don’t actually use rm, but have disabled it and use an alias to move files and directories into the Trash. Use at your own risk.)

Now you should be able to git add . and git commit, and the code from the submodule should be included in the umbrella project’s git repo. Once you push to Github, all the code should be in place.