Resume fails when UUID= syntax used in conf.d/resume

[Glenn Washburn]

I've having this issue on Bionic, but it appears that Focal still has this issue (and its probably been there for years). This can easily be reproduced by starting with a system on which hibernation is working using the resume=UUID=... kernel parameter. Then create the file /etc/initramfs-tools/conf.d/resume with contents RESUME=UUID=... Next regenerate the initrd and remove the resume= kernel parameter. Now hibernate the machine and when booted back up resume will fail. This contradicts expected behavior noted in the documentation.

This is because there is a bug on this line https://git.launchpad.net/ubuntu/+source/initramfs-tools/tree/scripts/local-premount/resume?h=ubuntu/focal#n35. The variable resume is of the form UUID=..., but of course readlink doesn't understand that. I've fixed this by inserting the line 'resume=${DEV}' above line 35.