This is issue is very old (I initially faced it on Xcode 11) and I wonder why Apple has not fixed it yet. There are many times that you are working for multiple companies or for customers of your company that have their own workspaces set up and provide different email addresses to software engineers. Every time I need to add a Swift Package dependency I have to rename my ~/.gitconfig and then remember to name it back with the proper name in order for this to work.