Ejabberd.Config.EjabberdModule.fetch_git_repos

You're seeing just the function fetch_git_repos, go back to Ejabberd.Config.EjabberdModule module for more information.
Link to this function

fetch_git_repos(modules)

Specs

fetch_git_repos([t()]) :: none()

Given a list of modules, it takes only the ones with a git attribute and tries to fetch the repo, then, it install them through :ext_mod.install/1