Test jstests/replsets/rollback_waits_for_bgindex_completion.js runs an index build in the background while a transaction is waiting to be committed, leader steps down, and rollsback the txn. Test verifies that rollback should wait for the index build to be aborted but it seems from the logs that there is no wait happening--rollback proceeds immediately because abort of index build has occurred earlier. We should investigate if the current behavior makes for a correct test, and possibly introduce a delay in aborting the index build so rollback effectively waits for it.

Please refer to ticket https://jira.mongodb.org/browse/SERVER-59687 for more information.