So memtest86 finished a complete pass successfully ("Finished pass #1 (of 4) (Total errors: 0, ECC errors: 0)"). Given the rate at which boots fail, I don't consider a second pass sensible.
Also ran dpkg -V to see if maybe the kernel image was corrupted or something, but that doesn't seem to be the case either.
Also ran dpkg -V to see if maybe the kernel image was corrupted or something, but that doesn't seem to be the case either.

