So we have a few questions on similar scenarios on meta, but generally the answer seems to have been 'mark as dupe'.
In this case, a user has created multiple account sand asked the same question twice. Normally we'd be able to mark the question as a duplicate when the user is the same, but since this user has two different accounts, the normal rules of duplicates get applied and it requires one of them to be answered.
It looks like people have started trying to close under other reasons, but yeah, at present, even though it's clear to all involved, there's no way to close as duplicate until one is answered - which could be a day, or it could be months.
Surely this is a case that needs addressing? I get that we don't allow dupes when there's no answers, but perhaps if it's the same user, it should be allowed?