Comment 4 for bug 42299

More specifically, the hibernate function works by writing a memory image to the swap partition. When the kernel boots, if there is a resume= entry in the boot arguments, the kernel loads the memory image, then restores the swap partition status.

Because the resume=<device> entry is missing, the kernel does not see the hibernation data. As the swapfile no longer has the correct signature, the swap partition will never be used again (Unless you do mkswap device (eg mkswap /dev/hda5))

I will re-assign this as major as it both undermines system functionality by permanently disabling swapfile, could cause data loss through suspended programs data never being written, and has an environmental impact as the hibernate function can enable the user to turn the computer off where otherwise it must be left turned on.