[Libguestfs] guestmount failing to mount a qcow image

I've been able to mount this image with qemu-nbd on Fedora 15 with: mkdir pb.test cd pb.test wget http://www.pixelbeat.org/guestfs/annoying.qcow2.gz wget http://www.pixelbeat.org/guestfs/77de68daecd823babbb58edb1c8e14d7106e83bb... gzip -d *.gz mkdir -p /var/lib/nova/instances/_base/ mv 77* /var/lib/nova/instances/_base/ modprobe nbd qemu-nbd -c /dev/nbd1 annoying.qcow2 mkdir t mount /dev/nbd1 t ls t umount t qemu-nbd -d /dev/nbd1 However guestmount on RHEL6.2 and Fedora 15 does this: # guestmount --rw -a /tmp/disk -i /tmp/tmplFlBCc libguestfs: error: mount_options: mount_options_stub: /dev/root: No such file or directory guestmount: some filesystems could not be mounted (ignored) # echo $? 0 # ls -lrt /tmp ls: cannot access /tmp/tmplFlBCc: Input/output error d?????????? ? ? ? ? ? tmplFlBCc I've attached the debug output from the above run on RHEL6.2 cheers, Pádraig.