- a single test is failing under CoreCLR only
- using the resource-related properties of a `ValidationAttribute` in
precisely one place – the failing test.
- in .NET the DataAnnotations assembly is somehow able to get access to
`internal` resources
- that doesn’t work under CoreCLR
- short-term fix is to add an `[InternalsVisibleTo]` in the test
assembly, giving DataAnnotations access to the resource
Will also file a bug in the DataAnnotations repo
a626896b80