git: empty commit message

When working with frameworks, like Ruby on Rails, there’s always the “initial commit” for all the files when commiting the first files for the application.

source

For me, I would like to have this “initial commit” to be the first commit into an empty repository, for example, the folder itself. The first commit is a blank slate and represents the start of the universe.

Let’s see what happens when trying to make an empty commit in a new repository:

vagrant@ubuntu$ git init
Initialized empty Git repository in /home/andrew/empty_commit/.git/
vagrant@ubuntu$ git commit -m 'start of the universe'
On branch master

Initial commit

nothing to commit
vagrant@ubuntu$ git log
fatal: your current branch 'master' does not have any commits yet

Trying to create an empty commit of just the folder did not work… I want to have a commit that contains a message “start of the universe” and has not files or folders.

Documentation to the Rescue

Just looking around to see if there’s a solution, I dove deep into git’s helper flags ($ git commit -h), man pages ($ man git commit), but nothing helped.

A search pointed me to git-scm, one of the best git documentation.

Looking at git-scm’s documentation on git commit page reveals:

–allow-empty Usually recording a commit that has the exact same tree as its sole parent commit is a mistake, and the command prevents you from making such a commit. This option bypasses the safety, and is primarily for use by foreign SCM interface scripts.

Source

git has an option to make an “empty” commit, exactly what I am looking for. Let’s see it working:

vagrant@ubuntu$ git commit --allow-empty -m 'start of the universe'
[master (root-commit) 9962d96] start of the universe
vagrant@ubuntu$ 
vagrant@ubuntu$ git log
commit 9962d967cfc661b9c73427c617f13e1c15e44752 (HEAD -> master)
Author: Andrew Leung <[email protected]>
Date:   Thu Apr 18 18:35:46 2019 -0400

    start of the universe
vagrant@ubuntu$

Cool - so now I can have empty commits in git, to indicate the “start of the universe”.

Conclusion

For those situations where an empty commit is necessary, use: $ git commit --allow-empty.

I like to use this when I start a project, I feel like I am “starting the universe”.