guestfs hang

[root@kvm]# libguestfs-test-tool
     ************************************************************
     *                    IMPORTANT NOTICE
     *
     * When reporting bugs, include the COMPLETE, UNEDITED
     * output below in your bug report.
     *
     ************************************************************
LIBGUESTFS_APPEND=edd=off
PATH=/usr/lib64/qt-3.3/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin
SELinux: Enforcing
library version: 1.20.11rhel=6,release=2.el6
guestfs_get_append: edd=off
guestfs_get_attach_method: appliance
guestfs_get_autosync: 1
guestfs_get_cachedir: /var/tmp
guestfs_get_direct: 0
guestfs_get_memsize: 500
guestfs_get_network: 0
guestfs_get_path: /usr/lib64/guestfs
guestfs_get_pgroup: 0
guestfs_get_qemu: /usr/libexec/qemu-kvm
guestfs_get_recovery_proc: 1
guestfs_get_selinux: 0
guestfs_get_smp: 1
guestfs_get_tmpdir: /tmp
guestfs_get_trace: 0
guestfs_get_verbose: 1
host_cpu: x86_64
Launching appliance, timeout set to 600 seconds.
libguestfs: launch: attach-method=appliance
libguestfs: launch: tmpdir=/tmp/libguestfspx9994
libguestfs: launch: umask=0077
libguestfs: launch: euid=0
libguestfs: command: run: febootstrap-supermin-helper
libguestfs: command: run: \ --verbose
libguestfs: command: run: \ -f checksum
libguestfs: command: run: \ /usr/lib64/guestfs/supermin.d
libguestfs: command: run: \ x86_64
supermin helper [00000ms] whitelist = (not specified), host_cpu = x86_64, kernel = (null), initrd = (null), appliance = (null)
supermin helper [00000ms] inputs[0] = /usr/lib64/guestfs/supermin.d
checking modpath /lib/modules/2.6.32-279.el6.x86_64 is a directory
picked vmlinuz-2.6.32-279.el6.x86_64 because modpath /lib/modules/2.6.32-279.el6.x86_64 exists
checking modpath /lib/modules/2.6.39-200.24.1.el6uek.x86_64 is a directory
picked vmlinuz-2.6.39-200.24.1.el6uek.x86_64 because modpath /lib/modules/2.6.39-200.24.1.el6uek.x86_64 exists
supermin helper [00000ms] finished creating kernel
supermin helper [00000ms] visiting /usr/lib64/guestfs/supermin.d
supermin helper [00000ms] visiting /usr/lib64/guestfs/supermin.d/base.img
supermin helper [00000ms] visiting /usr/lib64/guestfs/supermin.d/daemon.img
supermin helper [00000ms] visiting /usr/lib64/guestfs/supermin.d/hostfiles
supermin helper [00020ms] visiting /usr/lib64/guestfs/supermin.d/init.img
supermin helper [00020ms] visiting /usr/lib64/guestfs/supermin.d/udev-rules.img
supermin helper [00020ms] adding kernel modules
supermin helper [00051ms] finished creating appliance
libguestfs: checksum of existing appliance: 4805d2b09b84366bd753e62706693476b59c3971f4c1808739426b92f8baa3bf
libguestfs: [00054ms] begin testing qemu features
libguestfs: command: run: /usr/libexec/qemu-kvm
libguestfs: command: run: \ -nographic
libguestfs: command: run: \ -help
libguestfs: command: run: /usr/libexec/qemu-kvm
libguestfs: command: run: \ -nographic
libguestfs: command: run: \ -version
libguestfs: qemu version 0.12
libguestfs: command: run: /usr/libexec/qemu-kvm
libguestfs: command: run: \ -nographic
libguestfs: command: run: \ -machine accel=kvm:tcg
libguestfs: command: run: \ -device ?
libguestfs: [00182ms] finished testing qemu features
libguestfs: accept_from_daemon: 0x2266e00 g->state = 1
[00183ms] /usr/libexec/qemu-kvm \
    -global virtio-blk-pci.scsi=off \
    -nodefconfig \
    -nodefaults \
    -nographic \
    -machine accel=kvm:tcg \
    -cpu host,+kvmclock \
    -m 500 \
    -no-reboot \
    -kernel /var/tmp/.guestfs-0/kernel.47903 \
    -initrd /var/tmp/.guestfs-0/initrd.47903 \
    -device virtio-scsi-pci,id=scsi \
    -drive file=/tmp/libguestfs-test-tool-sda-Iakpwe,cache=none,format=raw,id=hd0,if=none \
    -device scsi-hd,drive=hd0 \
    -drive file=/var/tmp/.guestfs-0/root.47903,snapshot=on,id=appliance,if=none,cache=unsafe \
    -device scsi-hd,drive=appliance \
    -device virtio-serial \
    -serial stdio \
    -device sga \
    -chardev socket,path=/tmp/libguestfspx9994/guestfsd.sock,id=channel0 \
    -device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
    -append 'panic=1 console=ttyS0 udevtimeout=600 no_timer_check acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1 TERM=xterm edd=off'
\x1b[1;256r\x1b[256;256H\x1b[6n
Google, Inc.
Serial Graphics Adapter 10/14/11
SGABIOS $Id: sgabios.S 8 2010-04-22 00:03:40Z nlaredo $ (mockbuild@ca-build44.us.oracle.com) Fri Oct 14 20:04:36 UTC 2011
Term: 80x24
4 0
SeaBIOS (version seabios-0.6.1.2-28.el6)
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