I also probably can't test hibernation, never managed to get it working before. I'll give it a shot tomorrow though if I have time but I don't even have swap set up ATM.
That’s a pity, but okay, of course. Thanks for reporting this bug.
Since you are using Arch and the Wiki is quite detailed, you could try setting up a swap on an unused USB stick floating around. This should be the easiest setup. Make sure to add resume to the mkinitcpio hooks after udev, but before fsck and add the resume parameter to your bootloader as described in the Wiki. This should get you going.
Don’t make this a permanent setup, if you use encryption or like performance. The permanent solution would be creating a swap partition or, if that is not feasible, a swap file while considering the Wiki notes for e.g. btrfs.
Best regards, Manuel