Can't upgrade to os883 official from XO 1.75

[Lionel Laské]

Hi all,

Playing with the XO 1.75 B1, I'm trying to upgrade to os883 official.
I've got an error message (see below), both when I upgrading from an
USB key or online.
Sounds like a developer key missing. Do I need a developer key for an
official release on XO 1.75 ?
FYI I've just update to q4c10 firmware.

Thanks for your help.

Best regards from France.

              Lionel

[olpc at xo-c5-b9-5d ~]$ sudo olpc-update official_xo1.75-883
Traceback (most recent call last):
  File "/usr/sbin/olpc-update", line 11, in <module>
    from bitfrost.update.setup import shorten_hash
  File "/usr/lib/python2.6/site-packages/bitfrost/update/__init__.py",
line 5, in <module>
    from setup import perform_update, inhibit_suspend, check_signature
  File "/usr/lib/python2.6/site-packages/bitfrost/update/setup.py",
line 11, in <module>
    from bitfrost.leases.keys import OS_KEYS, DEVELOPER_KEYS
  File "/usr/lib/python2.6/site-packages/bitfrost/leases/keys.py",
line 52, in <module>
    raise Exception("OFW is not mounted, cannot read deployment keys")
Exception: OFW is not mounted, cannot read deployment keys
[olpc at xo-c5-b9-5d ~]$