Empty lists behaving incorrectly

[ChristopherChudzicki]

We're in the process of upgrading from version 0.10.5 to version 0.11.5, and empty list validation is now giving strange errors:

from voluptuous import Schema, Required, MultipleInvalid

schema = Schema({
    Required('variables', default=[]): []
})

try:
    schema({'variables': ['x']})
except MultipleInvalid as error:
    print(error)
# in 0.10.5: not a valid value for dictionary value @ data['variables']
# in 0.11.5: not a valid value for dictionary value @ data['x']

The error message doesn't make sense to me...there is no dictionary with key 'x'.

[alecthomas]

That seems like a bug.