git checkout tag, git pull fails in branch

Question

Edit: For newer versions of Git, --set-upstream master has been deprecated, you should use --set-upstream-to instead:

git branch --set-upstream-to=origin/master master

---

As it prompted, you can just run:

git branch --set-upstream master origin/master

After that, you can simply run git pull to update your code.

I had the same problem and fixed it with this command:

$ git push -u origin master

From the help file the -u basically sets the default for pulls:

-u, --set-upstream`

  For every branch that is up to date or successfully pushed, add 
  upstream (tracking) reference, used by argument-less git-pull(1) and
  other commands. For more information, see branch.<name>.merge in 
  git-config(1).

Try these commands:

git pull origin master
git push -u origin master

Switch back to the master branch using

$ git checkout master

and then run the git pull operation

$ git pull origin/master

Afterwards, you can switch back to your my_branch again.

@alesko : it is not possible to only do only git pull after checkout my_branch to update master branch only.
Because git pull will also merge to the current branch -> in your scenario to the my_branch

@Simon: that will do also the push. why is that?

$ git branch -u origin/master
Branch master set up to track remote branch master from origin.

and acording to docs:

-u <upstream>
  Set up <branchname>'s tracking information so <upstream> is considered  
  <branchname>'s upstream branch. If no <branchname> is specified,  
  then it defaults to the current branch.

First, make sure you are on the right branch.
Then (one time only):

git branch --track

After that this works again:

git pull