Responds to an error in the application's configured format.
Reads the responder published under ERROR_RESPONDER_STATE_KEY and
delegates to it. When no conforming responder is present — no errorHandler
registered at all — writes the framework-default { error: title } body
(plus detail when the init carries one) as application/json,
byte-identical to the shape the framework wrote before this seam existed.
The kernel's pre-pipeline sites (the drain 503, the malformed-request
400, and the request-lifecycle-hook failures) run before any middleware, so
the kernel seeds the application's resolved responder — read from the
pipeline's ERROR_RESPONDER_BRAND — into their state before this
call; with an errorHandler registered they answer in the configured format
exactly like every in-pipeline site.
A state value that is not a conforming responder is ignored (the fallback is
written) rather than thrown through, so a misconfigured or third-party state
value can never turn an error response into a 500.
Responds to an error in the application's configured format.
Reads the responder published under
ERROR_RESPONDER_STATE_KEYand delegates to it. When no conforming responder is present — noerrorHandlerregistered at all — writes the framework-default{ error: title }body (plusdetailwhen the init carries one) asapplication/json, byte-identical to the shape the framework wrote before this seam existed. The kernel's pre-pipeline sites (the drain503, the malformed-request400, and the request-lifecycle-hook failures) run before any middleware, so the kernel seeds the application's resolved responder — read from the pipeline'sERROR_RESPONDER_BRAND— into their state before this call; with anerrorHandlerregistered they answer in the configured format exactly like every in-pipeline site.A state value that is not a conforming responder is ignored (the fallback is written) rather than thrown through, so a misconfigured or third-party state value can never turn an error response into a
500.