How to resolve conflicts github

Resolving a merge conflict on GitHub

You can resolve simple merge conflicts that involve competing line changes on GitHub, using the conflict editor.

You can only resolve merge conflicts on GitHub that are caused by competing line changes, such as when people make different changes to the same line of the same file on different branches in your Git repository. For all other types of merge conflicts, you must resolve the conflict locally on the command line. For more information, see «Resolving a merge conflict using the command line.»

Warning: When you resolve a merge conflict on GitHub, the entire base branch of your pull request is merged into the head branch. Make sure you really want to commit to this branch. If the head branch is the default branch of your repository, you’ll be given the option of creating a new branch to serve as the head branch for your pull request. If the head branch is protected you won’t be able to merge your conflict resolution into it, so you’ll be prompted to create a new head branch. For more information, see «About protected branches.»

Under your repository name, click

Pull requests.

In the «Pull Requests» list, click the pull request with a merge conflict that you’d like to resolve.

Tip: If the Resolve conflicts button is deactivated, your pull request’s merge conflict is too complex to resolve on GitHub. You must resolve the merge conflict using an alternative Git client, or by using Git on the command line. For more information see «Resolving a merge conflict using the command line.»

If you have more than one merge conflict in your file, scroll down to the next set of conflict markers and repeat steps four and five to resolve your merge conflict.

If you have more than one file with a conflict, select the next file you want to edit on the left side of the page under «conflicting files» and repeat steps four through seven until you’ve resolved all of your pull request’s merge conflicts.

Once you’ve resolved all your merge conflicts, click Commit merge. This merges the entire base branch into your head branch.

If prompted, review the branch that you are committing to.

If the head branch is the default branch of the repository, you can choose either to update this branch with the changes you made to resolve the conflict, or to create a new branch and use this as the head branch of the pull request.

If you choose to create a new branch, enter a name for the branch.

If the head branch of your pull request is protected you must create a new branch. You won’t get the option to update the protected branch.

Click Create branch and update my pull request or I understand, continue updating BRANCH. The button text corresponds to the action you are performing.

To merge your pull request, click Merge pull request. For more information about other pull request merge options, see «Merging a pull request.»

About merge conflicts

In this article

Merge conflicts happen when you merge branches that have competing commits, and Git needs your help to decide which changes to incorporate in the final merge.

Git can often resolve differences between branches and merge them automatically. Usually, the changes are on different lines, or even in different files, which makes the merge simple for computers to understand. However, sometimes there are competing changes that Git can’t resolve without your help. Often, merge conflicts happen when people make different changes to the same line of the same file, or when one person edits a file and another person deletes the same file.

You must resolve all merge conflicts before you can merge a pull request on GitHub. If you have a merge conflict between the compare branch and base branch in your pull request, you can view a list of the files with conflicting changes above the Merge pull request button. The Merge pull request button is deactivated until you’ve resolved all conflicts between the compare branch and base branch.

Resolving merge conflicts

To resolve a merge conflict, you must manually edit the conflicted file to select the changes that you want to keep in the final merge. There are a couple of different ways to resolve a merge conflict:

If you have a merge conflict on the command line, you cannot push your local changes to GitHub until you resolve the merge conflict locally on your computer. If you try merging branches on the command line that have a merge conflict, you’ll get an error message. For more information, see «Resolving a merge conflict using the command line.»

Resolving a merge conflict using the command line

In this article

You can resolve merge conflicts using the command line and a text editor.

Merge conflicts occur when competing changes are made to the same line of a file, or when one person edits a file and another person deletes the same file. For more information, see «About merge conflicts.»

Tip: You can use the conflict editor on GitHub to resolve competing line change merge conflicts between branches that are part of a pull request. For more information, see «Resolving a merge conflict on GitHub.»

Competing line change merge conflicts

To resolve a merge conflict caused by competing line changes, you must choose which changes to incorporate from the different branches in a new commit.

For example, if you and another person both edited the file styleguide.md on the same lines in different branches of the same Git repository, you’ll get a merge conflict error when you try to merge these branches. You must resolve this merge conflict with a new commit before you can merge these branches.

Navigate into the local Git repository that has the merge conflict.

Generate a list of the files affected by the merge conflict. In this example, the file styleguide.md has a merge conflict.

Open your favorite text editor, such as Atom, and navigate to the file that has merge conflicts.

Add or stage your changes.

Commit your changes with a comment.

You can now merge the branches on the command line or push your changes to your remote repository on GitHub and merge your changes in a pull request.

Removed file merge conflicts

To resolve a merge conflict caused by competing changes to a file, where a person deletes a file in one branch and another person edits the same file, you must choose whether to delete or keep the removed file in a new commit.

For example, if you edited a file, such as README.md, and another person removed the same file in another branch in the same Git repository, you’ll get a merge conflict error when you try to merge these branches. You must resolve this merge conflict with a new commit before you can merge these branches.

Navigate into the local Git repository that has the merge conflict.

Generate a list of the files affected by the merge conflict. In this example, the file README.md has a merge conflict.

Open your favorite text editor, such as Atom, and navigate to the file that has merge conflicts.

Decide if you want keep the removed file. You may want to view the latest changes made to the removed file in your text editor.

To add the removed file back to your repository:

To remove this file from your repository:

Commit your changes with a comment.

You can now merge the branches on the command line or push your changes to your remote repository on GitHub and merge your changes in a pull request.

How to Resolve GitHub Merge Conflicts

June 19, 2018

Stay connected

Ten years ago, I was just starting out in my career as a developer. Back then, I was using subversion for my version control—then I came across Git. I remember how thrilled I was to find that Git worked way better than subversion. Subversion requires a workaround just to have branches. In Git, branching is a first-class citizen: explicitly available without your having to use weird workarounds. Merging code is a lot smoother in Git as well. In other words, Git was an awesome invention, one that spawned the business GitHub shortly thereafter. GitHub became everybody’s remote Git repository starting in early 2008. Not too long after Git and GitHub emerged, this question appeared on Stack Overflow:

With more than 4,000 votes and 33 different answers, this is clearly a popular question for developers. In this article, I will explore how to handle merge conflicts in these common scenarios:

Sending pull requests in GitHub

Pulling remote changes to a local repository

Performing a merge and rebase

At the end, I’ll wrap up by going through some simple ways to keep merge conflicts from happening in the first place.

In this scenario, I deliberately created a merge conflict (it’s harder than you might think!) with two separate feature branches. Both feature branches (I’m calling them section1 and section2) branched off from the same controller branch but got merged back to the controller branch via pull requests at different times. As you might expect, the pull request that got merged first had no issue. But when I tried to merge the second pull request, I got a merge conflict.

You should expect to see something like the image below at the pull request when you’re facing a merge conflict. Notice how GitHub disabled the merge pull request button. There’s also an additional message about conflicts in the branch. There are two possible situations at this point:

The Resolve conflicts button is available.

The Resolve conflicts button is NOT available. Usually this happens because the conflicts are more complicated.

I will proceed assuming the first scenario. The second has the same solution as when you fetch remote changes locally and experience the merge conflict. In that scenario, the resolution has to be done locally first. (I’ll talk more about how to resolve merge conflicts locally later on.)

Resolve within GitHub’s Web Editor

Click on Resolve conflicts and you should see the entire display of the changed files in the pull request. Notice that GitHub has disabled the Mark as resolved button.

Resolve the conflicts in the first file you see.

Ensure that all traces of >>>>>, and ====== are removed.

If you do this correctly, you should see the button Mark as resolved become available for that particular file.

If you have multiple files with conflicts, select the next file to resolve. Repeat steps two through four until you’ve resolved all of your pull requests’ merge conflicts.

Now the Commit merge button is available.

Click Commit merge and carry on with your merge pull request.

Now that you know how to resolve merge conflicts when sending pull requests to GitHub, it’s only right that you also learn how to resolve merge conflicts that arise when you fetch remote changes from GitHub. This section will also cover how to deal with the more complicated merge conflicts that GitHub does not let you resolve, as we touched on in the first section. Let’s get started:

Trigger the merge conflict by git merge feature/add-section2.

Now you have basically two choices to resolve your conflict:

You can open up your favorite IDE or code editor and go through the conflicts one at a time. Some editors might even help you by flagging the actual files.

You can use native mergetools available in your system (I will cover this in the next section).

Essentially, you are doing the same thing here as with the GitHub web editor example by removing the >>>> and

Typing git status will render a statement about unmerged paths.

You may add more comments or you can simply keep it as it is. Stage the change and you are done.

Setting up Mergetools

If you are using a mac, you have a range of available mergetools for you. These include meld, opendiff, vimdiff, and tortoisediff. To activate these tools, simply type git mergetool the moment after you’ve triggered a local merge conflict.

You can choose to configure your mergetool. Typing » ` git config merge.tool vimdiff ` » will configure vimdiff as the mergetool of choice. You can also install other mergetools if you like. Finally, to trigger the mergetool, simply type git mergetool again. Here’s a look at the mergetool I use. I prefer FileMerge, which opendiff is responsible for triggering.

Sometimes, you’ll want to merge and rebase at the same time and you’ll fail due to a merge conflict. You might still be able to perform the regular merge on its own, or you might not. But let’s say you insist on doing it with the rebase. What do you do? Once again, we’re trying to merge and rebase the feature/add-section2 branch into the controller branch. You can only do this locally. Let’s dive in:

Resolve the merge conflict as per normal.

Now you can go to GitHub to perform the merge and rebase.

How to Reduce Merge Conflicts

So far, I have covered various ways to resolve merge conflicts under the three most common scenarios:

Sending pull requests to GitHub

Fetching remote changes from GitHub

Attempting to merge and rebase

I have also added some helpful information about how to set up your mergetool, should you desire to do so. Before I conclude, I want to save you some future headaches by showing you how to reduce the number of merge conflicts you generate in the first place. As the saying goes, an ounce of prevention is worth more than a pound of cure. Here are three useful steps to help reduce merge conflict headaches you may have. Bear in mind, though: merge conflicts are inevitable. You can decrease them, but you can never fully eliminate them.

Fetch Remote Changes Frequently to Avoid Big Conflicts

Fetch remote changes frequently from the main branches and then handle the changes upstream. While you may need to resolve merge conflicts more frequently, this means that you’ll be resolving smaller conflicts each time. Resolving merge conflicts can get pretty hairy, especially for big projects with dozens of collaborators where the codebase runs into millions of lines.

Have Fewer Developers Working off the Same Branch

Merge conflicts increase tremendously when you have many people working on separate features and trying to merge back to the same branch. This is where your project manager can help. He or she will likely plan release branches from the controller branch and then break the release branches into smaller feature branches, which in turn can be further subdivided. Good old divide and conquer, I say.

Implement Feature Flags Management Solution with Trunk-Based Development

Instead of handling multiple feature branches, a more straightforward method may be to implement feature flags. Employ a feature flag management solution that allows for trunk-based development. This is especially crucial when it comes to early-stage development, when features are often dropped or changed drastically based on feedback. It’s worth it for your velocity and developer sanity to have a cleaner way to reduce merge conflicts. Sometimes, resolving merge conflicts can feel like writing the same code twice. Avoid unnecessary complications; create an environment where your developers (and you!) can be more productive. That’s it! You are now fully equipped with all the knowledge you’ll need to handle those pesky merge conflicts. If you think your colleagues will find this guide useful, do share it with them. They will thank you for it.

How to Resolve GitHub Merge Conflicts

Learn methods for resolving merge conflicts in GitHub, as well as tips for preventing them in the first place, in this tutorial.

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Ten years ago, I was just starting out in my career as a developer. Back then, I was using subversion for my version control — then I came across Git. I remember how thrilled I was to find that Git worked way better than subversion. Subversion requires a workaround just to have branches. In Git, branching is a first-class citizen: explicitly available without your having to use weird workarounds. Merging code is a lot smoother in Git as well.

In other words, Git was an awesome invention, one that spawned the business GitHub shortly thereafter. GitHub became everybody’s remote Git repository starting in early 2008.

Not too long after Git and GitHub emerged, this question appeared on Stack Overflow:

With more than 4,000 votes and 33 different answers, this is clearly a popular question for developers. In this article, I will explore how to handle merge conflicts in these common scenarios:

In the end, I’ll wrap up by going through some simple ways to keep merge conflicts from happening in the first place.

1. Conflicts From Sending Pull Requests in GitHub

In this scenario, I deliberately created a merge conflict (it’s harder than you might think!) with two separate feature branches. Both feature branches (I’m calling them section1 and section2) branched off from the same master branch but got merged back to the master branch via pull requests at different times. As you might expect, the pull request that got merged first had no issue. But when I tried to merge the second pull request, I got a merge conflict.

You should expect to see something like the image below at the pull request when you’re facing a merge conflict.

Notice how GitHub disabled the merge pull request button. There’s also an additional message about conflicts in the branch.

There are two possible situations at this point:

I will proceed assuming the first scenario. The second has the same solution as when you fetch remote changes locally and experience the merge conflict. In that scenario, the resolution has to be done locally first. (I’ll talk more about how to resolve merge conflicts locally later on.)

Resolve Within GitHub’s Web Editor

2. Conflicts From Pulling Remote Changes to a Local Repository

Now that you know how to resolve merge conflicts when sending pull requests to GitHub, it’s only right that you also learn how to resolve merge conflicts that arise when you fetch remote changes from GitHub. This section will also cover how to deal with the more complicated merge conflicts that GitHub does not let you resolve, as we touched on in the first section.

Let’s get started:

How to Reduce Merge Conflicts

So far, I have covered various ways to resolve merge conflicts under the three most common scenarios:

I have also added some helpful information about how to set up your mergetool, should you desire to do so. Before I conclude, I want to save you some future headaches by showing you how to reduce the number of merge conflicts you generate in the first place. As the saying goes, an ounce of prevention is worth more than a pound of cure. Here are three useful steps to help reduce merge conflict headaches you may have. Bear in mind, though: merge conflicts are inevitable. You can decrease them, but you can never fully eliminate them.

Fetch Remote Changes Frequently to Avoid Big Conflicts

Fetch remote changes frequently from the main branches and then handle the changes upstream. While you may need to resolve merge conflicts more frequently, this means that you’ll be resolving smaller conflicts each time. Resolving merge conflicts can get pretty hairy, especially for big projects with dozens of collaborators where the codebase runs into millions of lines.

Have Fewer Developers Working Off the Same Branch

Merge conflicts increase tremendously when you have many people working on separate features and trying to merge back to the same branch. This is where your project manager can help. He or she will likely plan release branches from the master branch and then break the release branches into smaller feature branches, which in turn can be further subdivided. Good old divide and conquer, I say.

Implement Feature Flags Management Solution With Trunk-Based Development

Instead of handling multiple feature branches, a more straightforward method may be to implement feature flags. Employ a feature flag management solution that allows for trunk-based development. This is especially crucial when it comes to early-stage development, when features are often dropped or changed drastically based on feedback. It’s worth it for your velocity and developer sanity to have a cleaner way to reduce merge conflicts. Sometimes, resolving merge conflicts can feel like writing the same code twice. Avoid unnecessary complications; create an environment where your developers (and you!) can be more productive.

That’s it! You are now fully equipped with all the knowledge you’ll need to handle those pesky merge conflicts. If you think your colleagues will find this guide useful, do share it with them. They will thank you for it.

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