This is a testharness.js-based test.
[FAIL] img without alt within a figure with figcaption
  assert_equals: <img src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==" data-testname="img without alt within a figure with figcaption" data-expectedlabel="figcaption" class="ex"> expected "figcaption" but got ""
Harness: the test ran to completion.