Git failed to push some refs

At some point when pushing your code to a remote server (e.g. GitHub, Bitbucket, GitLab) you’re going to see an error like the following

To github.com:salcode/myrepo.git
 ! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to 'git@github.com:salcode/myrepo.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Integrate the remote changes (e.g.
hint: 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

The important part here is “Updates were rejected because the tip of your current branch is behind its remote counterpart.”

How did this happen?

Typically, someone else has pushed code to your remote server that you do not yet have.

What you wanted to happen

Imagine the commits for both your local master branch and the remote server origin/master branch look something like

master     origin/master

cem32k     cem32k
b4d2o1     b4d2o1
abc123     abc123

(If viewing your Git branch as a list of commits like this seems unfamiliar, I suggest checking out my post on How to Improve Git Log)

Once you’re comfortable with the commits above, you add a new commit (dg34mp) to your local (master) branch.

master     origin/master

dg34mp     
cem32k     cem32k
b4d2o1     b4d2o1
abc123     abc123

Then you use

git push

and the remote server origin/master is brought up-to-date.

master     origin/master

dg34mp     dg34mp     
cem32k     cem32k
b4d2o1     b4d2o1
abc123     abc123

This is what we wanted to happen.

What really happened

While you were creating your new commit (dg34mp) on your local (master) branch, someone else added their own commit (zyx911) to the remote server

master     origin/master

dg34mp     zyx911
cem32k     cem32k
b4d2o1     b4d2o1
abc123     abc123

Now when you use

git push

Git says, “Whoa, hold on! I can’t add the dg34mp commit because there is an extra commit on the remote server we haven’t taken into account!” (a.k.a. I don’t know how to handle zyx911, “failed to push some refs”).

What do we do?

First, we make a backup copy of our master branch, in case something goes wrong. (This isn’t strictly necessary because of git reflog, but I find making a backup branch quicker and involving less thought). Once we make this backup branch we’re going to ignore it and ultimately when we’re done with this process we can delete it.

git branch bkup

Now, we rebase our master branch with the remote branch origin/master.

git rebase origin/master

This replaces our local master branch with the remote origin/master and then adds our new commit (dg34mp) on top.

master     origin/master

dg34mp
zyx911     zyx911
cem32k     cem32k
b4d2o1     b4d2o1
abc123     abc123

Now we can push our changes to the remote server (origin/master)

git push

and there is no problem because we are simply adding our new commit (dg34mp) to the remote branch.

Photo Credit

Marina del Castell

Sal Ferrarello (@salcode)

Sal is a PHP developer with a focus on the WordPress platform. He is a conference speaker with a background including Piano Player, Radio DJ, Magician/Juggler, Beach Photographer, and High School Math Teacher. Sal can be found professionally at WebDevStudios, where he works as a senior backend engineer.