The scutil doesn't appear to have a reliable way to undo HostName that was set.
man scutil seems to indicate putting no value in the command will undo it, but doesn't seem to work.
--set pref [newval]
Updates the specified preference with the new value. If the new value is not specified on the com-
mand line then it will be read from standard input.
Supported preferences include: ComputerName LocalHostName HostName
The --set option requires super-user access.
What's the magic pill to undo HostName?

