How can I mount the root Data volume as writable on macOS 10.15 Beta 1 when booted into Single User Mode?
I remounted the root first with mount -uw / followed by mount -uw /System/Volumes/Data to remount the data overlay. Be careful not to add a trailing / because it'll fail with &quot;unknown special file or file system&quot; /System/Volumes/Data/
Both issued a bunch of error messages, but everything was writable after that (as verified by the output of mount and also by touching some files in / and ~.