I am on nixos https://nixos.org/channels/nixos-23.05.

No, this was what I found in the journalctl log.

I only ran sudo -i nixos-rebuild switch.

~$ sudo fsck.ext4 /dev/sda1e2fsck 1.46.6 (1-Feb-2023)/dev/sda1 has unsupported feature(s): FEATURE_C12e2fsck: Get a newer version of e2fsck!/dev/sda1: ********** WARNING: Filesystem still has errors **********

You are in emergency mode. After logging in, type "journalctl -xb" to view
system logs, "systemctl reboot" to reboot, "systemctl default" or "exit"
to boot into default mode.
Give root password for maintenance
(or press Control-D to continue):

I have edited my example to make it clearer. I mean that I am taken to an emergecy prompt to log in as root instead of to my desktop. There is no disk encryption. I have no lines with `boot.initrd.luks`.

No problem.

Thanks for this. I am definately going to check it out.