How to replace master branch with experiment branch

I have two branches: master and experiment. Both of them evolved separately and are very different now. Now I am ready to make experiment branch my master branch.

If I try

git checkout master
git merge experiment

I get tons and tons of error.

What is the easiest way to get experiment branch to become master without loosing all the history of experiment branch.

I have already created a backup of m开发者_运维技巧aster branch as release 1.0 like this

git checkout master
git checkout -b release_1

---

Assuming these are private branches (i.e. nobody else is working on them), you can just set master to experiment like this:

git checkout master
git reset --hard experiment

If these are public branches, you'll probably want to merge and resolve conflicts, as Jefromi explains.

---

There are a few possibilities here, depending on exactly what you mean by "replace". You almost certainly took the right approach to start with - merging is generally the way to go. The "errors" you saw were merge conflicts, presumably. If you know for sure that, whenever there's a conflict, you want to use the version from your experimental branch, you could do:

# resolve conflicts by taking the version from experimental
# non-conflicting content is merged normally
git checkout master
git merge -Xtheirs experimental

If you want to use the version in experimental for everything, not just where there are conflicts, there are a ton of ways (there's not actually a merge strategy for this). The simplest:

# do the merge the other way around
git checkout experimental
git merge -s ours master
git checkout master
git merge experimental

# do the merge the right way
git checkout master
git merge --no-commit experimental  # merge, but stop before committing
git checkout experimental .         # check out content, but don't switch branch
git commit                          # commit the merge

The ways others have suggested (reset --hard, branch -M) will work, sort of, but since they don't create a merge commit, your master branch moves in a non-fast-forward way, potentially causing headaches for others who need to pull from this repo. Generally, I'd say that's the right answer only if these branches are unpublished.

---

You can rename your branch (from experiment): git branch -M master