Comment 4 for bug 742967

I can reproduce this and I've been working on it with a debugger for the last day or so. The crash occurs when trying to read a line from grub.cfg after executing the 'if loadfont ... fi' block. 'set root=(loop0)' has been a source of trouble in the past, although I was fairly sure we'd fixed that; but I suspect that it may well be unrelated to that, and that it's either memory corruption somewhere deep inside GRUB, or else is a bug related to the specific layout of the NTFS filesystem (there's a "read out of range" error being thrown in the depths of the NTFS driver, although this could be a knock-on failure from something else; however, grub-fstest can read the whole of /ubuntu/disks/root.disk correctly, so it doesn't seem as simple as a straightforward filesystem driver bug).

When I've seen things like this in the past, they've gone away when I tried to build modified versions of GRUB to debug them. Thus, I'm using entirely non-invasive techniques here.