这通常是由于其他人或其他仓库推送到了相同的分支上，导致您的本地仓库和远程仓库之间存在冲突。
错误信息：
To github.com:8upersaiyan/CKmuduo.git ! rejected main -> main (fetch first) error: failed to push some refs to 'github.com:8upersaiyan/CKmuduo.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.
解决方法：
git config --global pull.rebase true # 设置默认为变基策略
git pull origin main #从远程同步到本地
解决完远程同步到本地的问题，在解决从本地到网络的同步：
使用：
git add .
git commit -m "解决冲突并更新"
git push origin main
把本地的修改推送到网络上。