How to make Git pick config conditionally

Git has a feature called Conditional Include using which I can make it use a different config file depending on the condition such as the repo directory name or branch name.

For example, depending on the repo directory name I could make Git automatically use a different email config for checking in commits. Here is how to do that:

• In my main ~/.gitconfig file, I introduce a conditional include using includeIf for repos that lie inside my ~/funrepos directory:

[user]
    name = Joe Guy
    email = joe.guy@foobar.com

[includeIf "gitdir:~/funrepos/"]
    path = ~/.gitconfig.funrepos

• I create the new Git config file ~/.gitconfig.funrepos with a different email to use for fun hack repos:

[user]
    email = fun.repos@foobar.com

Tried with: Git 2.17.1 and Ubuntu 18.04