今天在使用git推送本地仓库到远程时发生报错，特此记录。

错误过程

使用命令

git push -u origin master

推送本地仓库到远程仓库时发生如下报错：

To gitee.com:mobius8086/algorithm-learning.git
 ! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to 'gitee.com:mobius8086/algorithm-learning.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. If you want to integrate the remote changes,
hint: use 'git pull' before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

问题排查及解决

1.查看本地仓库和远程仓库是否建立联系

git remote -v

返回如下信息，本地和远程仓库联系正常

$ git remote -v
origin  git@gitee.com:mobius8086/algorithm-learning.git (fetch)
origin  git@gitee.com:mobius8086/algorithm-learning.git (push)

2.第一次推送的时候需要加上-u参数

git push -u origin master

-u参数的作用是将本地仓库分支和远程仓库分支建立联系，origin是远程仓库默认名字，master是本地仓库默认名字，仅仅知道仓库名字不足够，因为一个仓库下面可能有多个分支，所以使用-u参数指定默认分支

返回如下信息：

$ git push -u origin "master"
To gitee.com:mobius8086/algorithm-learning.git
 ! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to 'gitee.com:mobius8086/algorithm-learning.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. If you want to integrate the remote changes,
hint: use 'git pull' before pushing again.

问题依旧。

3.本地仓库和远程仓库第一次同步，也就是没有pull过程

执行如下命令，将本地仓库和远程仓库同步

git git pull origin master

返回信息：

$ git pull origin master
From gitee.com:mobius8086/algorithm-learning
 * branch            master     -> FETCH_HEAD
fatal: refusing to merge unrelated histories

依旧报错，refusing to merge unrelated histories(拒绝合并不相关的历史)

那么就需要考虑使用一种强制性的手段将本地和远程仓库合并了

4.使用rebase命令将本地和远程仓库同步

git pull --rebase origin master

返回信息

$ git pull --rebase origin master
From gitee.com:mobius8086/algorithm-learning
 * branch            master     -> FETCH_HEAD
Successfully rebased and updated refs/heads/master.

看到了successfully，打开本地仓库查看变化，可以看到远程的内容被合并到了本地，所以接下来可以进行仓库推送了

 git push --set-upstream origin master

返回信息：

$ git push --set-upstream origin master
Enumerating objects: 12, done.
Counting objects: 100% (12/12), done.
Delta compression using up to 12 threads
Compressing objects: 100% (10/10), done.
Writing objects: 100% (11/11), 392.84 KiB | 7.70 MiB/s, done.
Total 11 (delta 0), reused 0 (delta 0), pack-reused 0
remote: Powered by GITEE.COM [GNK-6.4]
To gitee.com:mobius8086/algorithm-learning.git
   e7c3b04..3ed5762  master -> master
branch 'master' set up to track 'origin/master'.

执行成功！