1 Push to origin ／master was rejected
参考：https://stackoverflow.com/questions/40142180/android-studio-git-push-rejected
2 failed to push some refs to
描述：
$ git push -u origin master
To git@github.com:******/Demo.git ! [rejected] master -> master (non-fast-forward) error: failed to push some refs to 'git@github.com:******/Demo.git' hint: Updates were rejected because the tip of your current branch is behind hint: its remote counterpart. Merge the remote changes (e.g. 'git pull') hint: before pushing again. hint: See the 'Note about fast-forwards' in 'git push --help' for details.
解决方案：
（1）.使用强制push的方法：
$ git push -u origin master -f
这样会使远程修改丢失，一般是不可取的，尤其是多人协作开发的时候。
（2）.push前先将远程repository修改pull下来
$ git pull origin master
$ git push -u origin master
（3）.若不想merge远程和本地修改，可以先创建新的分支：
$ git branch [name]
然后push
$ git push -u origin [name]
参考：《push本地代码到github出错》
3 fatal: refusing to merge unrelated histories
描述：这是从远程库pull项目，合并文件发生的异常
解决方案：在pull的时候添加 --allow-unrelated-histories。
$ git pull origin master --allow-unrelated-histories
参考：《 git无法pull仓库refusing to merge unrelated histories》
4 error:src refspec master does not match any
描述：在push项目的时候，引发该异常。
原因分析：目录中没有文件，空目录是不能提交上去的，获取没有add、commit文件直接进行push了。
解决方案：
$touch README
$git add README
$git commit -m 'first commit'
$git push origin master
参考：《error: src refspec master does not match any解决办法》
《error: src refspec master does not match any》
5 fatal: Authentication failed for 'https://github.com/ ...
描述：使用的https提交，在用SourceTree提交代码时候发生错误，返回的错误提示说：
fatal: Authentication failed for 'https://github.com/ ...
解决方案：重新执行Git config命令配置用户名和邮箱即可：
$git config -–global user.name "xxx"
$git config –-global user.email "xxx@xxx.com"
6 ! [rejected] master -> master (fetch first)
描述：To git@git.oschina.net:yangzhi/hello.git
! [rejected] master -> master (fetch first)
error: failed to push some refs to 'git@git.oschina.net:yangzhi/hello.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushin
hint: to the same ref. You may want to first merge the remote changes (e.g.
hint: 'git pull') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.
解决方案：
可以输入：$ git push -u origin master -f
