What‘s cause of the problem and why it happened?
老外的 git status or git diff 没有变化，可我在 .repo/manifests 执行git status 有变化
Answer is :
Find the root cause, all files under .repo/manifests were changed with their filemode, "git config core.filemode false" can fix this "Modify".
翻译过来就是，进入.repo/manifests 目录，然后执行 git config core.filemode false， 问题解决了。