Looks like it is not Travis-specific, but some tests are generally not working for non-EN case.
Apparently got broken with merging https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Wikibase/+/580369
First failing TravisCI build was: https://travis-ci.org/github/wikimedia/mediawiki-extensions-Wikibase/builds/664417187
For example failure from https://travis-ci.org/github/wikimedia/mediawiki-extensions-Wikibase/jobs/664417188
There was 1 failure: 1) Wikibase\Repo\Tests\Specials\SpecialMyLanguageFallbackChainTest::testExecute === Logs generated by test case [objectcache] [debug] MainWANObjectCache using store {class} {"class":"EmptyBagOStuff"} [Wikibase] [debug] {method}: setting {settingName} was given as a closure, resolve it to {logValue} {"method":"Wikibase\\Lib\\SettingsArray::getSetting","settingName":"conceptBaseUri","logValue":"'http:\/\/localhost\/entity\/'"} [wfDebug] [debug] IP: 127.0.0.1 {"private":false} [MessageCache] [debug] MessageCache using store {class} {"class":"HashBagOStuff"} [wfDebug] [debug] ParserFactory: using default preprocessor {"private":false} [Wikibase] [debug] {method}: setting {settingName} was given as a closure, resolve it to {logValue} {"method":"Wikibase\\Lib\\SettingsArray::getSetting","settingName":"dataRightsUrl","logValue":"''"} [Wikibase] [debug] {method}: setting {settingName} was given as a closure, resolve it to {logValue} {"method":"Wikibase\\Lib\\SettingsArray::getSetting","settingName":"dataRightsText","logValue":"''"} [GlobalTitleFail] [info] MessageCache::parse called with no title set. {"exception":{}} [GlobalTitleFail] [info] MessageCache::parse called with no title set. {"exception":{}} === Cannot find 'ru - ' in the list of fallback languages in '<div class="mw-specialpage-summary"> <p>(mylanguagefallbackchain-summary) </p> </div><p>(wikibase-mylanguagefallbackchain-text) </p><ul><li>qqx - </li><li>en - English</li></ul>'. Failed asserting that false is of type "int". /home/travis/build/wikimedia/phase3/extensions/Wikibase/repo/tests/phpunit/includes/Specials/SpecialMyLanguageFallbackChainTest.php:35 /home/travis/build/wikimedia/phase3/tests/phpunit/MediaWikiIntegrationTestCase.php:416 /home/travis/build/wikimedia/phase3/maintenance/doMaintenance.php:99