Until PhantomJS is upgraded to version 1.9.2 Accept-Language feature will fail: https://integration.wikimedia.org/ci/job/mwext-browsertests-UniversalLan guageSelector-phantomjs/95/console Change-Id: I7e923189f3cdcb95fe94d93d0bdf78488f7435c4
Please see https://github.com/wikimedia/mediawiki-selenium for instructions on how to run tests.