It's rare, but when it happens it's indeed annoying.
Last night I ran the updates on my #ArchLinux system and noticing there was a new kernel version I shut down my machine instead of suspending it as usual.
This morning my OS wasn't booting.
I thought it was my fault and tried to revert some stuff I was trying by chrooting into my system from a usb.
No luck, until I tried to boot into the backup LTS kernel, and it worked.
Turns out the update broke something with the nvidia driver.