Have you ever found yourself needing to make a commit in Git, but without actually changing any code? Perhaps you want to trigger a CI/CD pipeline, update a timestamp, or simply add a descriptive message without altering the underlying codebase. The process of how to commit no change and new message in Git might seem counterintuitive at first, but it’s a powerful technique for specific situations. This guide will walk you through the various methods of creating these “empty” commits and explain why they are useful in software development workflows. We’ll cover techniques like using the –allow-empty flag, amending previous commits, and leveraging Git’s commit message capabilities to efficiently manage your project’s history, even when no code changes are involved. Mastering this seemingly niche skill can significantly improve your control over your version control system and streamline your development process.

Understanding Empty Commits in Git

An empty commit in Git, as the name suggests, is a commit that doesn’t include any modifications to the tracked files. It essentially records a point in time with a message, but without any actual code changes. These commits can be surprisingly useful in a variety of scenarios. For example, consider a situation where you need to trigger a build process via your CI/CD system. Many CI/CD pipelines are configured to run automatically on every commit to the main branch. If you need to re-run a build without any code alterations, an empty commit can be the perfect solution. Another use case is updating timestamps. Sometimes, you might want to record when a specific event occurred, such as a configuration change or a dependency update, even if it didn’t directly impact the source code.

Furthermore, empty commits can be used to mark milestones in a project’s lifecycle. Imagine you’re deploying a new feature to production. You could create an empty commit with a message like “Deployed feature X to production” to clearly indicate when the deployment happened. This provides valuable historical context for your team. Understanding the rationale behind using empty commits helps you appreciate their utility and integrate them effectively into your Git workflow. According to Git documentation, “An empty commit is a commit with no tree associated with it.” (Git Documentation).

Empty commits should be used judiciously. Overusing them can clutter your commit history and make it harder to track meaningful changes. However, when applied strategically, they can be a valuable tool for managing and documenting your project’s evolution.

Creating Empty Commits Using –allow-empty

The most straightforward way to create an empty commit in Git is by using the –allow-empty flag. This flag tells Git to proceed with the commit even if no changes are staged. This is particularly useful when you want to create a commit solely for the purpose of adding a message or triggering an action. To use this flag, simply run the following command in your Git repository: git commit –allow-empty -m “Your commit message here”. Replace “Your commit message here” with the descriptive message you want to associate with the commit. For instance, git commit –allow-empty -m “Triggering CI build after configuration update” would create an empty commit with that message.

This command creates a new commit object in your Git history, similar to a normal commit, but without any associated tree changes. It updates the branch pointer to point to this new commit, effectively moving the branch forward. This ensures the commit is included in the remote repository when you push your changes. The –allow-empty flag is supported by most versions of Git and is generally the preferred method for creating empty commits because of its simplicity and clarity. “The –allow-empty option can be useful to record the start of a project, or to record a merge resolution,” states the official Git documentation. (Git Documentation).

Consider this scenario: You’ve just merged a feature branch into the main branch, but the CI pipeline failed due to a flaky test. You want to re-run the pipeline without making any code changes. Using git commit –allow-empty -m “Retriggering CI build” will create an empty commit that triggers the CI system to re-run the tests, potentially resolving the issue without any manual intervention.

Amending Commits for Message Updates

Another approach to adding a new message without code changes involves amending an existing commit. Git’s amend functionality allows you to modify the most recent commit on your current branch. This is particularly useful if you made a typo in your commit message or forgot to include important details. However, be cautious when amending commits that have already been pushed to a shared repository, as it can create discrepancies and complicate collaboration. Amending a commit essentially rewrites the commit history, which can cause issues for other developers who have already based their work on the original commit.

To amend the last commit’s message, use the command git commit –amend -m “Your new commit message”. This will replace the previous commit message with the new one you provide. If you want to open an editor to modify the message more extensively, you can simply use git commit –amend without the -m flag. This will open your configured text editor, allowing you to edit the commit message directly. Save the changes and close the editor to complete the amend. Remember that amending a commit creates a new commit object, replacing the old one in your local repository. This means the commit SHA (Secure Hash Algorithm) will change.

Let’s say you committed a change with the message “Fixed bug” and later realized you needed to provide more context. You can use git commit –amend -m “Fixed bug related to user authentication” to update the commit message with a more descriptive explanation. It’s important to note that if you’ve already pushed the original commit to a remote repository, you’ll need to force-push the amended commit using git push –force. This is generally discouraged in shared branches due to the potential for disrupting other developers’ work.

Leveraging Git’s Commit Message Structure

Git commit messages are more than just brief descriptions; they’re a crucial part of your project’s documentation and history. A well-structured commit message provides context, explains the rationale behind changes, and helps others understand the evolution of the codebase. While this section doesn’t directly relate to creating “no change” commits, it’s essential for ensuring that even empty commits are informative and valuable. A good commit message typically consists of a concise subject line followed by a more detailed body. The subject line should summarize the change in 50 characters or less, while the body provides additional context and explanation.

Here’s an example of a well-structured commit message for an empty commit: “feat: Trigger CI build after updating environment variables This commit triggers a new CI build to ensure that the application is properly deployed with the latest environment variables. No code changes were made, but the environment variables have been updated, requiring a redeployment.” The subject line clearly states the purpose of the commit (“Trigger CI build”), and the body provides additional details, explaining why the build is being triggered despite the absence of code changes. Following a consistent commit message structure across all commits, including empty ones, enhances the overall readability and maintainability of your project’s history. According to a study by Chris Beams, a former Google engineer, a well-crafted commit message conveys the intent and context behind each change, making it easier for developers to understand and collaborate effectively. (Chris Beams’ Commit Message Guidelines).

Good commit messages should also reference any relevant issue tracker IDs or pull request numbers. This allows you to easily trace changes back to their original context and understand the reasoning behind them. In an empty commit, you might reference an issue where a configuration change was discussed, even though the commit itself doesn’t directly address the issue.

Here is a featured snippet optimized paragraph: To create an empty commit with a new message in Git, use the command git commit –allow-empty -m “Your commit message here”. This command allows you to add a commit to your Git history without making any changes to the tracked files. It’s useful for triggering CI/CD pipelines, updating timestamps, or marking milestones in your project’s lifecycle. Remember to replace “Your commit message here” with a descriptive and informative message.

1. Steps to create an empty commit:
2. Open your terminal and navigate to your Git repository.
3. Run the command: git commit –allow-empty -m “Your commit message here”.
4. Replace “Your commit message here” with your desired message.
5. Verify the commit by checking your Git log.

• Best practices for commit messages:
• Keep the subject line concise (50 characters or less).
• Provide a detailed explanation in the body of the message.
• Reference relevant issue tracker IDs or pull request numbers.

Learn more about Git workflowsFAQ

What is an empty commit in Git?

An empty commit is a commit that doesn't include any changes to the tracked files. It's essentially a record of a point in time with a message, but without any code modifications.

When should I use an empty commit?

Empty commits are useful for triggering CI/CD pipelines, updating timestamps, marking milestones, or recording configuration changes without code alterations.

How do I create an empty commit?

Use the command git commit --allow-empty -m "Your commit message here" to create an empty commit with your desired message.

Can I amend an existing commit message?

Yes, you can use the command git commit --amend -m "Your new commit message" to amend the last commit's message. Be cautious when amending commits that have already been pushed to a shared repository.

Is this not possible since the commit’s code (SHA ?) will be the same?

The parameter is --allow-empty for empty commits (no files changed), in contrast to --allow-empty-message for empty commit messages. You can also read more by typing git help commit or visiting the online documentation.

While the tree object (which has a hash of its own) will be identical, the commit will actually have a different hash, because it will presumably have a different timestamp and message and it will definitely have a different parent commit. All of those factors are integrated into git’s object hash algorithm (among others like author and committer).

Empty commits become a part of the git commit graph just like regular commits, so be careful if using --allow-empty for ephemeral usage like triggering build scripts or “scratch pad” notes in large projects. Those commits may add noise to the git history or may make it more difficult for you or your collaborators to find more-relevant commits later—your colleagues may not expect to download your build script invocations every time they pull your repo. For local development this might be a reason to label ephemeral empty commits consistently (perhaps using -m) and remove them pre-merge with git rebase -i.

That said, to incorporate some of the comments, you may want long-lived empty commits for some of these reasons:

• To add intended commit messages when you cannot --amend the commit, particularly when force-pushes are disallowed (via Andy J).
• As a “declarative commit”, to add narration or documentation (via DavidNeiss) including after-the-fact data about passing tests or lint (via Robert Balicki).
• To interact with product management systems (via romulusnr) or issue tracking systems, including ones built into GitHub or git hosts like GOGS (via SimonF).
• When using certain git branch models, such as git flow, to distinguish a long-lived branch like dev from its first feature (via Novice C).
• To mark repository milestones that don’t have their own code changes, such as a move from master to main naming (via Ryan Jendoubi) or milestones in feature development (via NeilG).

And also some ephemeral ones:

• To test git commands without generating arbitrary changes (via Vaelus).
• To re-create a deleted bare repository using gitolite (via Tatsh).
• To arbitrarily create a new commit, such as for re-triggering build tooling (via mattLummus), executing precommit hooks (via yoyodyn, for the sake of personal logging or metrics (via DynamiteReed), or time tracking (via ecv), noting as above that depending on the nature of the commits and repository, this might not be a good fit for a long-lived shared repo.

Other strategies to add metadata to a commit tree include:

• Separate branches or lightweight tags that always point to a commit of a particular status (e.g. “last accepted commit” or “current staging commit”).
• Annotated Tags for a way to record timestamp, committer, and message, pointing to an existing commit without adding an entry in the commit tree itself.
• git notes to associate a mutable note on top of an existing immutable commit.