s!!! Failed to open file: '/mnt/livecd/usr/livecd/db/pkg/gnome-base/gnome-common-2.12.0/SLOT.3540'
!!! [Errno 30] Read-only file system: '/mnt/livecd/usr/livecd/db/pkg/gnome-base/gnome-common-2.12.0/SLOT.3540'
Traceback (most recent call last):
  File "/usr/bin/emerge", line 28, in ?
    portage.global_updates(
  File "/usr/lib/portage/pym/portage.py", line 7073, in global_updates
    trees["/"]["vartree"].dbapi.move_slot_ent(update_cmd)
  File "/usr/lib/portage/pym/portage.py", line 4599, in move_slot_ent
    write_atomic(os.path.join(origpath, "SLOT"), newslot+"\n")
  File "/usr/lib/portage/pym/portage_util.py", line 696, in write_atomic
    f = atomic_ofstream(file_path)
  File "/usr/lib/portage/pym/portage_util.py", line 647, in __init__
    super(atomic_ofstream, self).__init__(tmp_name, mode=mode, **kargs)
IOError: [Errno 30] Read-only file system: '/var/db/pkg/gnome-base/gnome-common-2.12.0/SLOT.3540'