I have added a submodule and checked in this submodule fully, I have then checked in my master project.
Now my team mate who had checked out the master project before i added a submodule only gets an empty folder for the submodule.
he can do recursive checkout of master project and get submodule. But we don't want a new checkout because he has changes, so we simply want the submodule to show up in his project as well.
My thought is that he could git stash save
his changes, do a recursive checkout to get the changes and then git stash pop
to keep going.
I would test this out first to make sure it works how you expect it too.