As someone who code on multiple machines to work on different projects, I like to commit with different emails.
I don’t know how everyone else handle different emails in .gitconfig and track dotfiles in a git repo at the same time, but here’s the solution I’ve come up with.
First, I have a global ~/.gitconfig with the default user email and some other global settings (by global I mean same cross different computers I work on).
name = Default Name
email = firstname.lastname@example.org
Then for each machine I have a ~/.gitconfig-local file which can override some settings just for that machine, such as email, signing key, editor, etc.
email = email@example.com
Back in the global ~/.gitconfig, I have this snippet that tells git to also look for configuration in my ~/.gitconfig-local:
path = ~/.gitconfig-local
Here, I can have ~/.gitconfig tracked in my dotfiles repo, but I do not have ~/.gitconfig-local tracked. This way, I can put anything I like specific to a particular machine in the ~/.gitconfig-local, as well as SMTP settings such as password, which you wouldn’t want to end up in a public git repo.
As to setting it up on a new machine, I have a setup script in my dotfiles repo that creates an empty ~/.gitconfig-local. I use this same method with fish configs – global config and a local config, you can have a look at them in my dotfiles repo on sourcehut.