Read-only file system 。百度出来的文章是关闭系统文件保护，但其实并不是官方方案，官方建议使用
SYNOPSIS synthetic.conf -- synthetic symbolic link and directory manifest DESCRIPTION synthetic.conf describes virtual symbolic links and empty directories to be created at the root mount point. Because the root mount point is read- only as of macOS 10.15, physical files may not be created at this loca- tion. All writeable paths must reside on the data volume, which is mounted at /System/Volumes/Data. synthetic.conf provides a mechanism for some limited, user-controlled file-creation at /. The synthetic entities described in this file are synthesized by the kernel during early system boot. They are not physi- cally present on the disk, but when the system is booted, they behave as if they were within certain parameters. synthetic.conf is intended to be used for creating mount points at / (e.g. for use as NFS mount points in enterprise deployments) and symbolic links (e.g. for creating a package manager root without modifying the system volume). synthetic.conf is read by apfs.util(8) during early sys- tem boot.
sudo vim /etc/synthetic.conf # 添加一行记录(如果有两列需要使用 tab 进行分割，注意空格分割是无效的)，然后重启即可 # 举例 app /Users/houfc/app # 将会在根目录下创建 app 软连接到根目录下的 /Users/houfc/app 目录
lrwxr-xr-x 1 root wheel 16 10 13 18:33 /app -> /Users/houfc/app