Comment 4 for bug 1962359

> Is the swap space big enough?

A good point. This worked on previous versions on Ubuntu with swap (18GB) only 50% of RAM (32GB). I recreated my /swapfile with 38GB and the same issue persists. ie.

$ free -m
               total ...
Mem: 31964
Swap: 38911

> Furthermore, the hibernation failure isn't logged in the dmesg.

That's correct. The machine just stalls with a blank screen. It's still awake as is apparent by motherboard lights. It cannot be awoken in any way and needs to cold restarted using power button.

Curiously if I run smem before I attempt to hibernate, it does not show any processes using swap. ie

$ smem --columns="swap" --no-header | tr -d " " | awk '$1 != 0' | wc -l
0