$ git push origin master
git@gitee.com: Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
需要设置公钥：
ssh-keygen -t rsa -C 'zhuhuitao_struggle@163.com'
生成公钥
$ git push -u origin master
To gitee.com:SixtecCloud/sixtec-cloud-android-repo.git
! [rejected] master -> master (fetch first)
error: failed to push some refs to 'gitee.com:SixtecCloud/sixtec-cloud-android-repo.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.
$ git pull origin master
remote: Enumerating objects: 2778, done.
remote: Counting objects: 100% (2778/2778), done.
remote: Compressing objects: 100% (1836/1836), done.
remote: Total 2778 (delta 847), reused 2772 (delta 847), pack-reused 0
Receiving objects: 100% (2778/2778), 55.85 MiB | 10.21 MiB/s, done.
From gitee.com:SixtecCloud/sixtec-cloud-android-repo
* branch master -> FETCH_HEAD
* [new branch] master -> origin/master
fatal: refusing to merge unrelated histories
当执行完pull后，再次提交：
$ git push -u origin master
To gitee.com:SixtecCloud/sixtec-cloud-android-repo.git
! [rejected] master -> master (non-fast-forward)
error: failed to push some refs to 'gitee.com:SixtecCloud/sixtec-cloud-android-repo.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Integrate the remote changes (e.g.
hint: 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.
hint: Updates were rejected because the tip of your current branch is behind
出现这个错误的原因是git本地仓库的当前版本低于远程仓库的版本(大白话就是：你在github上进行的修改没有同步到本地git仓库中)。
在终端下输入：git push -u origin master -f
这句话执行的后果就是在远程仓库中进行的相关修改会被删除，使远程仓库回到你本地仓库未修改之前的那个版本，
然后上传你基于本地仓库的修改。这如果在企业开发中就会让别的程序员的这些天的开发付之东流，一切回到解放前。
相关解决办法：
https://blog.csdn.net/IT_SoftEngineer/article/details/107133313
