我只有分支主和我得到这个错误，每次我尝试“git拉”:

error: Couldn't set refs/remotes/origin/master
From /var/lib/git/xxx/project
 ! a0f80ea..49177a3  master     -> origin/master  (unable to update local ref)

当我执行“git pull origin master”时，我得到:

error: Couldn't set ORIG_HEAD
fatal: Cannot update the ref 'ORIG_HEAD'.

我一直在寻找，却找不到原因