Dunno which extension is at fault:
https://integration.wikimedia.org/ci/job/mediawiki-extensions-zend/18603/consoleFull
```
22:23:07 There was 1 error:
22:23:07
22:23:07 1) SpecialMobileDiffTest::testNames with data set #0 ('123', true)
22:23:07 MWException: Diff not implemented for Flow\Content\BoardContent; override generateContentDiffBody to fix this.
22:23:07
22:23:07 /mnt/jenkins-workspace/workspace/mediawiki-extensions-zend/src/includes/diff/DifferenceEngine.php:790
22:23:07 /mnt/jenkins-workspace/workspace/mediawiki-extensions-zend/src/includes/diff/DifferenceEngine.php:733
22:23:07 /mnt/jenkins-workspace/workspace/mediawiki-extensions-zend/src/extensions/MobileFrontend/includes/specials/SpecialMobileDiff.php:214
22:23:07 /mnt/jenkins-workspace/workspace/mediawiki-extensions-zend/src/extensions/MobileFrontend/includes/specials/SpecialMobileDiff.php:125
22:23:07 /mnt/jenkins-workspace/workspace/mediawiki-extensions-zend/src/extensions/MobileFrontend/tests/phpunit/specials/SpecialMobileDiffTest.php:22
22:23:07 /mnt/jenkins-workspace/workspace/mediawiki-extensions-zend/src/tests/phpunit/MediaWikiTestCase.php:131
```