I see the same error:

          ID: nova-manage db sync
    Function: cmd.run
        Name: nova-manage db sync; sleep 15
      Result: True
     Comment: Command "nova-manage db sync; sleep 15" run
     Started: 18:07:09.511897
    Duration: 17747.739 ms
     Changes:   
              ----------
              pid:
                  18000
              retcode:
                  0
              stderr:
                  No handlers could be found for logger "oslo_config.cfg"
                  2016-01-26 18:07:12.092 18001 DEBUG migrate.versioning.repository [-] Loading repository /usr/lib/python2.7/dist-packages/nova/db/sql
alchemy/migrate_repo... __init__ /usr/lib/python2.7/dist-packages/migrate/versioning/repository.py:76
                  2016-01-26 18:07:12.093 18001 DEBUG migrate.versioning.script.base [-] Loading script /usr/lib/python2.7/dist-packages/nova/db/sqlalc
hemy/migrate_repo/versions/216_havana.py... __init__ /usr/lib/python2.7/dist-packages/migrate/versioning/script/base.py:27
[...]
[...]
[...]
                  2016-01-26 18:07:12.157 18001 INFO migrate.versioning.api [-] 290 -> 291... 
                  2016-01-26 18:07:12.167 18001 CRITICAL nova [-] ValidationError: There are still 3 unmigrated flavor records. Migration cannot conti$
ue until all instance flavor records have been migrated to the new format. Please run `nova-manage db migrate_flavor_data' first.
                  2016-01-26 18:07:12.167 18001 ERROR nova Traceback (most recent call last):
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/bin/nova-manage", line 10, in <module>
                  2016-01-26 18:07:12.167 18001 ERROR nova     sys.exit(main())
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/nova/cmd/manage.py", line 1443, in main
                  2016-01-26 18:07:12.167 18001 ERROR nova     ret = fn(*fn_args, **fn_kwargs)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/nova/cmd/manage.py", line 910, in sync
                  2016-01-26 18:07:12.167 18001 ERROR nova     return migration.db_sync(version)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/nova/db/migration.py", line 26, in db_sync
                  2016-01-26 18:07:12.167 18001 ERROR nova     return IMPL.db_sync(version=version, database=database)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/nova/db/sqlalchemy/migration.py", line 106, in db_$
ync
                  2016-01-26 18:07:12.167 18001 ERROR nova     version)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/migrate/versioning/api.py", line 186, in upgrade
                  2016-01-26 18:07:12.167 18001 ERROR nova     return _migrate(url, repository, version, upgrade=True, err=err, **opts)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "<string>", line 2, in _migrate
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/migrate/versioning/util/__init__.py", line 160, in 
with_engine
                  2016-01-26 18:07:12.167 18001 ERROR nova     return f(*a, **kw)
                  2016-01-26 18:07:12.167 18001 ERROR nova     return migration.db_sync(version)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/nova/db/migration.py", line 26, in db_sync
                  2016-01-26 18:07:12.167 18001 ERROR nova     return IMPL.db_sync(version=version, database=database)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/nova/db/sqlalchemy/migration.py", line 106, in db_s
ync
                  2016-01-26 18:07:12.167 18001 ERROR nova     version)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/migrate/versioning/api.py", line 186, in upgrade
                  2016-01-26 18:07:12.167 18001 ERROR nova     return _migrate(url, repository, version, upgrade=True, err=err, **opts)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "<string>", line 2, in _migrate
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/migrate/versioning/util/__init__.py", line 160, in 
with_engine
                  2016-01-26 18:07:12.167 18001 ERROR nova     return f(*a, **kw)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/migrate/versioning/api.py", line 366, in _migrate
                  2016-01-26 18:07:12.167 18001 ERROR nova     schema.runchange(ver, change, changeset.step)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/migrate/versioning/schema.py", line 93, in runchan$
e
                  2016-01-26 18:07:12.167 18001 ERROR nova     change.run(self.engine, step)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/migrate/versioning/script/py.py", line 148, in run
                  2016-01-26 18:07:12.167 18001 ERROR nova     script_func(engine)
                  2016-01-26 18:07:12.167 18001 ERROR nova   File "/usr/lib/python2.7/dist-packages/nova/db/sqlalchemy/migrate_repo/versions/291_enfor$
e_flavors_migrated.py", line 35, in upgrade
                  2016-01-26 18:07:12.167 18001 ERROR nova     raise exception.ValidationError(detail=msg)
                  2016-01-26 18:07:12.167 18001 ERROR nova ValidationError: There are still 3 unmigrated flavor records. Migration cannot continue unt$
l all instance flavor records have been migrated to the new format. Please run `nova-manage db migrate_flavor_data' first.
                  2016-01-26 18:07:12.167 18001 ERROR nova
              stdout:
                  Command failed, please check log for more info
----------
 
Ubuntu 14.04, cloud-archive:liberty.