我有 2 个分支，master并且secondary它们通过合并定期保持同步master => secondary.
有一次，master有几个子模块被删除并重新添加了相同的子模块。
我现在正在尝试合并master，secondary但每当我尝试从 to 切换时master，secondary我都会在被覆盖的子模块上收到以下错误消息：
warning: unable to rmdir libs/AFNetworking: Directory not empty
warning: unable to rmdir libs/MBProgressHUD: Directory not empty
Branch secondary set up to track remote branch secondary from origin.
Switched to a new branch 'secondary'
'master' 分支是这样开始的：
git clone repourl:master.git
cd project_directory
git submodule update --init <= in master at the moment
git checkout secondary