self = <swh.storage.tests.test_in_memory.TestInMemoryStorage object at 0x7f100b741518> swh_storage = <swh.storage.in_memory.InMemoryStorage object at 0x7f1213a3e5f8> sample_data = <swh.storage.tests.storage_data.StorageData object at 0x7f100b734588> def test_revision_add_name_clash(self, swh_storage, sample_data): revision, revision2 = sample_data.revisions[:2] revision1 = attr.evolve( revision, author=Person( fullname=b"John Doe <john.doe@example.com>", name=b"John Doe", > email=b"john.doe@example.com", ), ) .tox/py3/lib/python3.7/site-packages/swh/storage/tests/storage_tests.py:970: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ inst = Revision(message=b'hello', author=Person(fullname=b'Nicolas Dandrimont <nicolas@example.com> ', name=b'Nicolas Dandrim...xbb\x12', extra_headers=((b'gpgsig', b'test123'), (b'mergetag', b'foo\\bar'), (b'mergetag', b'"\xaf\x89\x80\x01\x00'))) changes = {'author': Person(fullname=b'John Doe <john.doe@example.com>', name=b'John Doe', email=b'john.doe@example.com'), 'message': b'hello'} cls = <class 'swh.model.model.Revision'> attrs = (Attribute(name='message', default=NOTHING, validator=<function type_validator.<locals>._validator at 0x7f1218812510>,..., ...], converter=<function tuplify_extra_headers at 0x7f12187efae8>, kw_only=False, inherited=False, on_setattr=None)) a = Attribute(name='author', default=NOTHING, validator=<function type_validator.<locals>._validator at 0x7f1218812598>, r...ppingproxy({}), type=<class 'swh.model.model.Person'>, converter=None, kw_only=False, inherited=False, on_setattr=None) attr_name = 'author', init_name = 'author' value = Person(fullname=b'Nicolas Dandrimont <nicolas@example.com> ', name=b'Nicolas Dandrimont', email=b'nicolas@example.com') def evolve(inst, **changes): """ Create a new instance, based on *inst* with *changes* applied. :param inst: Instance of a class with ``attrs`` attributes. :param changes: Keyword changes in the new copy. Nested ``attrs`` classes can be updated by passing (nested) dicts of values. :return: A copy of inst with *changes* incorporated. :raise TypeError: If *attr_name* couldn't be found in the class ``__init__``. :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` class. .. versionadded:: 17.1.0 """ cls = inst.__class__ attrs = fields(cls) for a in attrs: if not a.init: continue attr_name = a.name # To deal with private attributes. init_name = attr_name if attr_name[0] != "_" else attr_name[1:] value = getattr(inst, attr_name) if init_name not in changes: # Add original value to changes changes[init_name] = value elif has(value): # Evolve nested attrs classes > changes[init_name] = evolve(value, **changes[init_name]) E TypeError: evolve() argument after ** must be a mapping, not Person .tox/py3/lib/python3.7/site-packages/attr/_funcs.py:347: TypeError