No real idea of where's best to file this, so putting it here as a stab in the dark. Lego, Keegan, please move as appropriate.
An enwiki user called Mirwin was renamed automatically to Mirwin~enwiki (more about that in a moment) but four edits he made a very long time ago got detached for some reason.
Regarding the renaming itself, the account belongs to a deceased editor who passed away without attaching it to the SUL for that name, which is User:Mirwin at Wikiversity. I've placed a steward request for the enwiki account to be renamed back to Mirwin and attached to the SUL.