Fått svar från Dave på supporten SuperDuper vilket används för cloningen. Efter denna operation fungerar det igen att starta från hårddisken:
Unfortunately, 10.15.5 has a bug in it that I discuss at http://www.shirt-pocket.blog. This bug causes the "system" and "data" Catalina volumes to not be connected with firmlinks.
As a one-time fix, assuming a backup of the startup volume, please open the Terminal application and type the following
sudo asr restore --erase --source / --target
followed by a space. Drag in the backup drive volume from your Desktop, which will be "typed" for you.
For example, if the backup drive is called "SuperDuper Backup", the command will end up being
sudo asr restore --erase --source / --target /Volumes/SuperDuper\ Backup
Press Return. Enter your password when prompted, press Return, allow it to erase the volume by typing “y” and then Return, wait for completion. There will be two “percent complete” bars - both have to finish and the prompt has to come back.
Note that the low level copy that's being done will also rename the backup to the same as the source. You can rename it back on completion.
Once done, you'll have a bootable backup, and subsequent Smart Updates will be able to maintain it as expected.
--
Dave Nanian
Shirt Pocket
