It seems the rsync job currently has a timeout of 3 minutes. The successful runs now take about 2.5 minutes for MediaWiki core, and in some cases slightly longer, thus getting discarded.
https://integration.wikimedia.org/ci/job/publish-to-doc1001/73099/console
00:00:00.001 Started by upstream project "mediawiki-core-doxygen-docker" build number 16595 … 00:00:00.003 Building remotely on contint2001 (dockerPublish pipelinelib blubber productionAgents train) in workspace /srv/jenkins-slave/workspace/publish-to-doc1001 … 00:00:00.154 [publish-to-doc1001] … 00:00:00.157 Fetching from: 00:00:00.157 - Instance...: 172.16.7.208 00:00:00.157 - Workspace..: /srv/jenkins/workspace/workspace/mediawiki-core-doxygen-docker 00:00:00.157 - Subdir.....: log/build/html 00:00:00.158 + rsync --archive --compress '--rsh=/usr/bin/ssh -a -T -o ConnectTimeout=6 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no' jenkins-deploy@172.16.7.208:/srv/jenkins/workspace/workspace/mediawiki-core-doxygen-docker/log/build/html/. . 00:02:32.238 Creating remote directory mediawiki-core/master/php 00:02:32.594 sending incremental file list 00:02:32.903 00:02:32.903 sent 110 bytes received 27 bytes 91.33 bytes/sec 00:02:32.903 total size is 0 speedup is 0.00 00:02:32.906 Publishing ... 00:02:32.907 + rsync --archive --compress --delete-after . rsync://doc1001.eqiad.wmnet/doc/mediawiki-core/master/php 00:03:00.113 Build timed out (after 3 minutes). Marking the build as failed. … 00:03:00.347 Finished: FAILURE