Saxon

Could you be more specific please? What message is being output to stdErr? Are messages being output related to individual invalidities, or just a single message at the end?

Sorry for the confusion. There's a message for each invalidity and one at the end.

Here's an example output of what I'm talking about:

Error on line 1 column 10 
  FORG0001  Required attribute @Q{}requiredAttribute is missing on element <element>
Error on line 1 column 50 
  FORG0001  In content of element <element>: The content model does not allow element
  <child3> to appear immediately after element <child1>. It must be preceded by <Q{}child2>. 
Error on line 1 column 60 
  XQDY0027  Two validation errors were reported. First error: Required attribute
  @Q{}requiredAttribute is missing on element <element>

OK, that definitely shouldn't be happening if you register your own InvalidityHandler. Can you supply a repro so we know exactly what you are doing?

Michael Kay wrote in RE: Suppress std err output during Schema validation:

OK, that definitely shouldn't be happening if you register your own InvalidityHandler. Can you supply a repro so we know exactly what you are doing?

Can do, once I get a moment later in the day.

After eliminating some of the extraneous code I realized that it's only the final summary message that's still being output to stderr once my InvalidityHandler is set.

Is there a way to intercept that somehow?

I've raised an issue regarding this message at https://saxonica.plan.io/issues/6068

It's complicated because of the number of different APIs for invoking validation, including the ability to invoke validation from XSLT and XQuery (in which case any invalidity is fatal).

I agree that in the case of validation invoked from the s9api SchemaValidator, the summary message (which is sent to the Configuration's Logger; the default Logger writes to StdErr) is inappropriate.