Git pull a certain branch from GitHub

But I get an error "! [rejected]" and something about "non fast forward"

That's because Git can't merge the changes from the branches into your current master. Let's say you've checked out branch master, and you want to merge in the remote branch other-branch. When you do this:

$ git pull origin other-branch

Git is basically doing this:

$ git fetch origin other-branch && git merge other-branch

That is, a pull is just a fetch followed by a merge. However, when pull-ing, Git will only merge other-branch if it can perform a fast-forward merge. A fast-forward merge is a merge in which the head of the branch you are trying to merge into is a direct descendent of the head of the branch you want to merge. For example, if you have this history tree, then merging other-branch would result in a fast-forward merge:

O-O-O-O-O-O
^         ^
master    other-branch

However, this would not be a fast-forward merge:

    v master
O-O-O
\
 \-O-O-O-O
         ^ other-branch

To solve your problem, first fetch the remote branch:

$ git fetch origin other-branch

Then merge it into your current branch (I'll assume that's master), and fix any merge conflicts:

$ git merge origin/other-branch
# Fix merge conflicts, if they occur
# Add merge conflict fixes
$ git commit    # And commit the merge!

Simply track your remote branches explicitly and a simple git pull will do just what you want:

git branch -f remote_branch_name origin/remote_branch_name
git checkout remote_branch_name

The latter is a local operation.

Or even more fitting in with the GitHub documentation on forking:

git branch -f new_local_branch_name upstream/remote_branch_name

You could pull a branch to a branch with the following commands.

git pull {repo} {remotebranchname}:{localbranchname}

git pull origin xyz:xyz

When you are on the master branch you also could first checkout a branch like:

git checkout -b xyz

This creates a new branch, "xyz", from the master and directly checks it out.

Then you do:

git pull origin xyz

This pulls the new branch to your local xyz branch.

The best way is:

git checkout -b <new_branch> <remote repo name>/<new_branch>

git fetch will grab the latest list of branches.

Now you can git checkout MyNewBranch

Done :)

For more info see docs: git fetch