DatabaseIntegrityError when changing from structural to unique in scratch file

dbintegrity.md

.> alias.type ##Text Text

structural ability MyAbility where
  foo: Text

.> update

unique ability MyAbility where
  foo2: Text

MyAbility.foo : '{MyAbility} Text
MyAbility.foo _ = "hi"

MyAbility.bar : '{MyAbility} Text
MyAbility.bar _ = !MyAbility.foo

.> update