If a loader's perform method raises an exception after all promises have been fulfilled, it's silently dropped

[tgwizard]

See

graphql-batch/lib/graphql/batch/loader.rb

Lines 65 to 77 in 3b22366

	def resolve #:nodoc:
	return if resolved?
	load_keys = queue
	@queue = nil
	around_perform do
	perform(load_keys)
	end
	check_for_broken_promises(load_keys)
	rescue => err
	reject_pending_promises(load_keys, err)
	end

If all promises are fulfilled, then reject_pending_promises will find nowhere to pass err, and it'll be dropped.

I stumbled on a case where this happened due to open-telemetry tracing instrumentation annotating a span with the exception.