Comment 9 for bug 1960457

What we mean is to boot an ISO like this:

menuentry "Ubuntu 22.04 ISO" {
  set iso_path=/path/to/jammy-desktop-amd64.iso
  loopback loop ${iso_path}
  linux (loop)/casper/vmlinuz iso-scan/filename=${iso_path} boot=casper --
  initrd (loop)/casper/initrd
}

This works for all versions <= 21.10.

For Jammy this does not work anymore, because with lupin-casper also the iso-scan/filename handler (scripts/casper-premount/20iso_scan) was removed.

Thus, every attempt ends with the error message:
Unable to find a medium containing a live file system