LaFontaine | An automatic movie trailer generator | Video Utils library

I leave this answer in reference.For solving the problem of updating the submodule on a pull, we need to understand how git submodule works.

Submodule are a nesting of a git repo in another git repo. In other words, the first Git (project) reference to another Git repo (the submodule, could be a library). When working with a standard submodule, it will be checked out as a detached Head with a specific SHA. This means that doing a pull on it will not update the project reference.

If the submodule is configured to follow a branch, than that would means that we expect the submodule to evolve and we also expect it to always conform to some standard to our project.

With this in mind, when we do a git pull we would like the submodule to be "checked out" to the revision we've configured (whether it be a specific commit or a branch). To do this, we can configure the "fetch" to be recursive on our config ;

git config --global fetch.recurseSubmodules true

I expect that being configured that way, you want to work with git submodules. Then this trick might be useful to see conflict in the submodule before doing a push;

git config --global push.recurseSubmodules check

ref:[https://chrisjean.com/git-submodules-adding-using-removing-and-updating/]