---
upgrade:
  - |
    The ``nova-manage`` set of commands would previously exit with return
    code 1 due to any unexpected error. However, some commands, such as
    ``nova-manage db archive_deleted_rows``,
    ``nova-manage cell_v2 map_instances`` and
    ``nova-manage placement heal_allocations`` use return code 1 for flow
    control with automation. As a result, the unexpected error return code
    has been changed from 1 to 255 for all ``nova-manage`` commands.