How can I reset to the main branch in git

Question

I want to make my current branch exactly the same as my main branch. When I do 'git reset --hard main', it does the job. But then when I push it complains that it is behind.

error: failed to push some refs to 'https://gitlab.bol.io/sequoia/relevanc.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.

I tried using logs but it doesn't work... just want to go back to the main branch... how to do this?

Answer 1

A branch in Git is merely a name for a commit. That's just about all it is. So the phrase "make my current branch exactly the same as my main branch" is ambiguous. What is it supposed to mean?

Let's say you have this:

A -- B -- C -- D <- main
      \
       X -- Y -- Z <- mybranch

When you say you want mybranch to be the same as main, you might mean one of two things (at least).

Possibility 1

You might mean: "I don't care about Z. I don't care about Y. I don't care about X. I'm sorry I ever made them. I'm sorry about all the work I've done on mybranch. I want mybranch to start all over, emanating from where main is now."

Then there is no need for all this violence (hard reset, force push, etc.). Just delete mybranch altogether! It serves no purpose:

git fetch
git switch --det origin/main
git branch -D mybranch
git push origin --delete mybranch

Now mybranch is gone — both locally and on the remote. If you now want to start over, with mybranch emanating from main, then start over: make mybranch:

git switch -c mybranch
git push origin mybranch

Result on the remote:

A -- B -- C -- D <- main, mybranch

As you can see, main and mybranch are the same commit, and the separate history of mybranch is effectively gone.

Possibility 2

You might mean: I want to keep X and Y and Z but I want the state of my project in mybranch to be identical to the state of my project in main.

Then you would reverse merge mybranch into main with the ours strategy, and then merge main into mybranch:

git fetch
git switch --det origin/main
git merge -s ours mybranch
git switch mybranch
git merge origin/main
git push origin mybranch

Result on the remote:

A -- B -- C -- D -- M (identical to D) <- main, mybranch
      \            /
       X -- Y -- Z

As you can see, main and mybranch now point to the same commit, M, which is identical (in content) to D, which was the state of main; but the history has been preserved.

Answer 2

I want to make my current branch exactly the same as my main branch.

$ git checkout <branchname>
$ git fetch origin/main
$ git reset --hard origin/main
$ git push --force-with-lease origin <branchname>

this will set the branch HEAD to the latest commit on the remote main branch. As you are rewriting the history of the branch, you will need to force push the branch (--force-with-lease) next time you push to the remote branch.