The following error was thrown while installing Oracle 19c database in red hat 8:

INS-08101 Unexpected error while executing the action at state: ‘SupportedOSCheck’

The solution:

in your .profile add the following environment variable entry:

export CV_ASSUME_DISTID=’OL7′

This is because 19c is an older released and was compatible with red hat 7 at the time.