linkml-validate error messages are not always clear or actionable

[turbomam]

Shared by @StroemPhi in the #linkml-dev channel in the obo-community Slack space

Error messages produced by linkml validate could greatly benefit from more detail. It took me quite some time to figure out on which slot my range error was as all I got was a generic "[whole schema dict] is not valid under any of the given schemas in [object with wrong slot]".

[turbomam]

Yes, I have received the same kinds of error messages when developing the nmdc-schema. When that happens I break my input data down into minimal test cases. That's a good learning experience but can be slow.

The superficial answer is that those error messages generally come directly from jsonschema.validate. Generally it comes from cases in which the data could legitimately be compared to two or more classes, or a LinkML class that can be reduced to two or more Json schema classes. For example, a class with a movie_publication_date slot that has

any_of:
  - range: integer
  - RomanNumeralsEnum

Json schema doesn't have any construct that matches that, so the LinML class is converted into two classes: one with a integer-range movie_publication_date slot and one with a a RomanNumeralsEnum-range movie_publication_date slot