Conflicto con los MRO en EnumerationAdapter

Traceback (most recent call last):
  File "/home/manu/src/merchise/pgi2/xhg/sources/dists/odoo/odoo/service/server.py", line 1235, in preload_registries
    registry = Registry.new(dbname, update_module=update_module)
  File "/home/manu/src/merchise/pgi2/xhg/sources/dists/odoo/odoo/modules/registry.py", line 86, in new
    odoo.modules.load_modules(registry._db, force_demo, status, update_module)
  File "/home/manu/src/merchise/pgi2/xhg/sources/dists/odoo/odoo/modules/loading.py", line 415, in load_modules
    processed_modules += load_marked_modules(cr, graph,
  File "/home/manu/src/merchise/pgi2/xhg/sources/dists/odoo/odoo/modules/loading.py", line 311, in load_marked_modules
    loaded, processed = load_module_graph(
  File "/home/manu/src/merchise/pgi2/xhg/sources/dists/odoo/odoo/modules/loading.py", line 194, in load_module_graph
    registry.setup_models(cr)
  File "/home/manu/src/merchise/pgi2/xhg/sources/dists/odoo/odoo/modules/registry.py", line 268, in setup_models
    model._setup_fields()
  File "/home/manu/.virtualenvs/xhg-00lsyyUm/lib/python3.8/site-packages/xoeuf/fields/enumeration/__init__.py", line 498, in _setup_fields
    _super_setup_fields(self)
  File "/home/manu/src/merchise/pgi2/xhg/sources/dists/odoo/odoo/models.py", line 2639, in _setup_fields
    field.setup_full(self)
  File "/home/manu/.virtualenvs/xhg-00lsyyUm/lib/python3.8/site-packages/xoeuf/fields/enumeration/__init__.py", line 311, in setup_full
    cls.__bases__ = (EnumerationAdapter,) + cls.__bases__
TypeError: Cannot create a consistent method resolution
order (MRO) for bases EnumerationAdapter, Step, Step, Step, Step, Step, Step, Step, mail.thread, mail.activity.mixin, xhg.autrement.pricing.inspector, xhg.autrement.pricing.rounding.def, base

Esto me dio cuando pasé el rounding_type de los pasos para un mixin para usarlo en los contratos: mercurio-2018/xhg2!1730. La lista de clases que componen el Step es larguita. No he podido reproducirlo aquí.