Untrashable Previous System
I've ended up with a Previous System folder on my main hard drive which claims to be "in use" when I try to trash it. I think it has been there for more than a year, but I've recently needed to carve our more space on my hard drive, and this folder is taking up 2GB.
I've restarted and booted in to Safe Boot mode which made no difference.
Since the system apparently believes these folders (they look like normal System folders such as Library/Frameworks) are active, how risky is it to blast away with the "sudo rm" command in Terminal (I know how to use the command, so no need for the warnings)? How is it the System is "reaching in" to this Previous System folder more than a year after I installed High Sierra on this Mac?