ansible role: Why do I have to set user.email in etckeeper?

I wrote [a ansible role to automate installing etckeeper](https://github.com/sourcejedi/ansible-etckeeper) . I discover that git will complain if I haven't configured user.email. In some circumstances, git commits will fail. This includes automatic commits to etckeeper when installing a package, potentially causing the install to fail. So I have to add a task for that, like [everyone else does :)](https://github.com/debops-contrib/ansible-etckeeper/blob/b56cc3496c76c3e2d44322748f3efa5422baa980/tasks/main.yml#L85) . The frustrating thing is that in some circumstances, it seemed to work ok. And it doesn't seem to be a problem when using etckeeper manually. user.email is never mentioned in the [tutorial](https://etckeeper.branchable.com/README/) . Is it actually necessary to set user.email in the Ansible role? If so... there must be _some_ deliberate reason(s) causing this. Some explanation, which I could put into a comment in the role, or which would justify a patch to etckeeper or git?