This test failed because it relies on [lang|=..] for results, but [lang|=..] is not supported by this browser.
A lang|= value will match a lang attribute value regardless of case differences.
This tests a detail related to [lang|=..] support. If [lang|=..] is not supported, a message will appear and the test will fail.
Spec text: «The case-sensitivity of attribute names and values in selectors depends on the document language.»