The key is "argument-less git-pull". When you do a git pull
from a branch, without specifying a source remote or branch, git looks at the branch.<name>.merge
setting to know where to pull from. git push -u
sets this information for the branch you're pushing.
To see the difference, let's use a new empty branch:
$ git checkout -b test
First, we push without -u
:
$ git push origin test
$ git pull
You asked me to pull without telling me which branch you
want to merge with, and 'branch.test.merge' in
your configuration file does not tell me, either. Please
specify which branch you want to use on the command line and
try again (e.g. 'git pull <repository> <refspec>').
See git-pull(1) for details.
If you often merge with the same branch, you may want to
use something like the following in your configuration file:
[branch "test"]
remote = <nickname>
merge = <remote-ref>
[remote "<nickname>"]
url = <url>
fetch = <refspec>
See git-config(1) for details.
Now if we add -u
:
$ git push -u origin test
Branch test set up to track remote branch test from origin.
Everything up-to-date
$ git pull
Already up-to-date.
Note that tracking information has been set up so that git pull
works as expected without specifying the remote or branch.
Update: Bonus tips:
git pull
this setting also affects default behavior of git push
. If you get in the habit of using -u
to capture the remote branch you intend to track, I recommend setting your push.default
config value to upstream
.git push -u <remote> HEAD
will push the current branch to a branch of the same name on <remote>
(and also set up tracking so you can do git push
after that).