问题
When you create a new repository and run git branch, it exits silently. For example:
$ mkdir /tmp/foo; cd /tmp/foo; git init
Initialized empty Git repository in /tmp/foo/.git/
$ git branch
Why doesn't the command provide any output, or show the master branch?
回答1:
TL;DR
No branch heads exist yet.
Detailed Explanation
A Git repository has no branches until you make your first commit. A newly-initialized repository sets HEAD to refs/heads/master, but refs/heads/master won't exist or contain a commit pointer until after the first commit is made.
During a commit, Git dereferences the symbolic-ref HEAD to find the head of the current branch, and then updates that head with the commit hash supplied by git-commit-tree.
The end result is that git branch has nothing to report in a new repository. With no branch heads present, it simply terminates silently with an exit status of zero.
See Also
- git-branch(1)
- git-commit-tree(1)
- git-symbolic-ref(1).
- git-update-ref(1)
- gitcore-tutorial(7)
回答2:
Note that a branch is simply a pointer to a commit.
Since an empty repo (with its empty tree) has no commit, you have no branch.
A first commit will create a branch named 'master', because HEAD references refs/heads/master.
Should you want to create a first commit on a different branch (than master), you would need to change the symbolic ref of HEAD first (as detailed in this thread):
git symbolic-ref HEAD refs/heads/non-master
And then make your first commit.
回答3:
Yes, you first need to perform
$ git add .
$ git commit -m 'first commit'
commands.
来源：https://stackoverflow.com/questions/11077919/why-is-git-branch-silent-in-new-repositories