I voted to close the following question as a duplicate: https://english.stackexchange.com/q/349088/142322.
The question already had one close vote, but not as a duplicate. After I voted, a mod voted to close as well, presumably not as a duplicate.
The problem is that the notice doesn't show the purported duplicate, and the usual comment about the possible duplicate didn't show up.
I'm logging this as a bug since it throws away useful information for the OP, namely, the link to the purported duplicate.
I thought there might be some information on Meta.ELU and Meta.SE, but the closest Meta questions I found were the following, none of which helped:
On Meta.SE from a search with the string "close duplicate missing notice is:question":