Granting a local user account administrator rights on a Mac which only has accounts with standard user rights

I recently saw a post on LinkedIn where the poster had apparently removed all accounts which were assigned administrator rights on the Mac from the local group named admin on macOS and then had difficulty recovering from this state.

On macOS, membership in the admin group is what grants administrator rights, so now this meant that the Mac only had accounts which had standard user rights.

There have been methods available in the past for fixing this from the Recovery environment which used the chroot command line tool in the Recovery environment to change the active filesystem from the Recovery environment to the Mac’s regular boot drive, then run the dseditgroup command line tool to re-add one or more local user accounts to the admin group on the boot drive.

However, it looks like the chroot command does not work currently in the Recovery environment available to macOS Tahoe on Apple Silicon Macs. When launched, it reports an error and then exits.

With the chroot command line tool no longer working in Recovery, that would seem to close off most avenues to re-adding users to the admin group for Apple Silicon Macs running macOS Tahoe. However, after some research, I’ve discovered an alternative method which uses the sudo command line tool. For more details, please see below the jump.