This is my first time trying to install Arch so my apologies if I don't understand your answer. Here is my problem. I am using the QEMU emulator (x86_64) to install Archlinux on a 128GB Samsung USB key. I am using QEMU because I am installing from macOS and from what I understand about Arch, it is like yogurt or bread.
I have managed to fully bootstrap and configure Arch (simple stuff, no KDE or anything yet), set up my ESP, install GRUB2 and rEFInd, and all that jazz. More notes on my installation process can be found on my previous question here.
The problem is that, since I am using QEMU, the UUID's for my partitions are all wrong when I do
genfstab /mnt >> /mnt/etc/fstab. Similarly, when I try to do
diskutil info disk2sX | grep -i UUID and manually change the FSTAB (and propagate the changes by reinstalling GRUB2), the UUID's are also wrong.
GRUB cannot mount the Arch partition in order to boot it, so I get dropped into the emergency shell, which (for some inexplicable reason ) does not connect the keyboard.
So: I have the wrong UUID's and no way of getting them. Is my sexy arch partition doomed?
 I understand the reason, honestly I just don't understand why the emergency shell has command line prompt at all since there is no case I can think of where the emergency shell is going to be able to use the keyboard anyway. Whatever, not the point.