When your distro-upgrade past comes back to haunt you...

A long, long time ago, I messed up while updating my (Arch) work box, and ended-up deleting /etc/fstab. Oops. Having to get back to work, I just hacked the two lines absolutely necessary to boot the box---the mounts for /home and /---and made a mental note to fix it properly later. I should have known better.

Predictably enough, I ended up never doing it---until now. Why? Well, because I use stable, and for a long time there had been no kernel updates---until now. Because /boot was unmounted, from the update process' point of view, it was a regular folder, so all the files that were modified were just dumped in there. Worse, because the /boot line did not exist in /etc/fstab, the system had no idea that /boot is where the boot partition is supposed to be mounted---otherwise during the upgrade process a very visible warning would have been displayed (I confirmed this specifically re-testing this scenario). And the day after, I turn on the box, only to discover that it boots just fine, but that's about it. After booting, in X, no keyboard, no mouse, no anything---because the system has the wrong modules loaded! (it has the ones that correspond to the kernel in the /boot folder, rather than the /boot partition, which is the one that is actually running, i.e. loaded during the boot process).

And so I had to borrow 5 minutes at a colleague's computer, to browse for the solution, so I can boot, so I can downgrade the kernel, fix fstab, re-upgrade the kernel, and finally get back to work. Murphy, I effing hate you!