[repo] normalize ValidationError on edited entity (closes #2509729) In CubicWeb, ValidationError.entity MUST be the eid of the involved entity, not the entity iteself (as done by yams).

from os.path import join
assert __file__.endswith(join('scripts', 'script1.py')), __file__
assert '__main__' == __name__, __name__
assert [] == __args__, __args__