https://www.cnblogs.com/lingear/p/6062093.html
Often used in the development process from the master branch copy a development branch, here we use the command line to complete this operation:
1. Switch to the copy branch (master), and the latest version from the distal end of the pull
$git checkout master
$git pull
2. The development branch from the current branch to pull copy
$git checkout -b dev
Switched to a new branch 'dev'
3. The new branch to the distal end of the push
$ git push origin dev
4. pulling the distal branches
$ git pull
There is no tracking information for the current branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.
git pull <remote> <branch>
If you wish to set tracking information for this branch you can do so with:
git branch --set-upstream-to=origin/<branch> dev
Verified, and the current branch is not associated with the local branch, the next step according to the prompt:
5. associated
Git Branch the --set-upstream $-to Origin = / dev
6. The pull verification again
$git pull