Seen on ConfirmEdit (CAPTCHA extension) patch https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/ConfirmEdit/+/588051/
https://integration.wikimedia.org/ci/job/wmf-quibble-vendor-mysql-php72-docker/29773/consoleFull
18:23:41 15 04 2020 17:23:41.181:DEBUG [middleware:source-files]: Requesting /index.php/Special:EntityData/null.json?revision=0 18:23:41 15 04 2020 17:23:41.182:DEBUG [middleware:source-files]: Fetching /index.php/Special:EntityData/null.json 18:23:41 15 04 2020 17:23:41.182:DEBUG [proxy]: proxying request - /index.php/Special:EntityData/null.json?revision=0 to 127.0.0.1:9412 18:23:41 15 04 2020 17:23:41.669:DEBUG [HeadlessChrome 73.0.3683 (Linux 0.0.0)]: CONFIGURING -> EXECUTING 18:23:41 WARN: 'Pending requests does not match jQuery.active count' 18:23:41 testrunner 18:23:41 ✖️ Setup 18:23:41 WARN: 'Pending requests does not match jQuery.active count' 18:23:41 ✖️ Teardown 18:23:41 WARN: 'Pending requests does not match jQuery.active count' 18:23:41 ✖️ Loader status 18:23:41 WARN: 'Pending requests does not match jQuery.active count' 18:23:41 ✖️ assert.htmlEqual 18:23:41 WARN: 'Pending requests does not match jQuery.active count' 18:23:41 testrunner-after 18:23:41 ✖️ Teardown