When an index build request finds than an identical index build is already in progress, it will normally return with an IndexBuildAlreadyInProgress error. This is retried internally by the createIndexes command.

If the in-progress build has already been aborted, but is slow to tear down, we propagate an IndexBuildAborted error code to the caller. This was done as part of SERVER-43612.

This masks the original cause of aborting the index build. If the index build was aborted by InterruptedDueToReplStateChange, a retryable error, the error code returned to the client is IndexBuildAborted, which is not retryable. This causes tests to break because they cannot retry this operation.