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I have been trying to add the ability to clone a Catalina System in my backup app code and have come up against the seemingly closed or hidden ApI for creating firmlinks. I am able to recreate the System and Data volumes using "diskutil apfs addVolume" but unable to create the firmlinked directories. I can see that CCC, SuperDuper and others have. I would like to provide for my users the needed cloning ability for Catalina. Just wondering what is required for developers to gain access?Thanks.