Sometimes we need to create a directory in root, but we don’t allow to write the root directory since Catalina and Big Sur. Apple provides another way to realise this purpose, by modifying the file:
/etc/synthetic.conf
e.g. I first create a folder in my home directory:
/Users/testuser/Qt
after then added the following entry in order to create a symbol link to /Qt
Qt Users/frank/Qt
Attension: the separator is Tab not space!!!!, after then save the file and reboot the system, you will see Qt has already been in the root directory.
testuser@Testers-MacBook-Pro / % pwd/testuser@Testers-MacBook-Pro / % lsApplications Qt Users bin dev home private tmp varLibrary System Volumes cores etc opt sbin usr
It works for Catalina and Big Sur.