I was configuring our new Lambda Razer Laptop to use a Smartcard for login. Made a mistake/typo in the common-auth file and locked myself out of sudo. Not a big deal - just re-install and start over right?
Well I have installed a new version of Ubuntu 20.04 from a USB, and yet it continues to boot up the original Ubuntu install. I had selected the new installation to overwrite the existing operating system, so I am not sure how this is happening.
Any clues on how to actually remove the original OS installation?
You do should be able to recover without needing to reinstall. You can boot into single user then remount the root file system as read/write and edit. Or boot from a USB drive if your drive is not encrypted.
It is likely you installed in a separate drive then, or in parallel and at the grub prompt you could choose another install, or on the BIOS you could select the other drive.
For things like this it is best to send to: support@lambdal.com
And someone can walk you through fixing this either way you would like.