This warning has been in local Vagrant logs for a long time but due to it not happening on every page view, it was presumably not noticed before. Since 976943c9913b, the severity of these violations has been raised to level "Warning" in production - in preparation for removing support for this error entirely.
This is being logged at a regular frequency from production wikis in the resourceloader channel. It's simple to fix (see parent task for more information.)
Unexpected general module "mobile.messageBox" in styles queue.