alt Hacker NewsIt’s certainly okay to link to a previous discussion, but “duplicate” implies that you think the present submission shouldn’t exist, and the previous submission doesn’t actually provide any discussion.
The fact that a previous submission didn’t gain traction isn’t usually interesting, because it can be pretty random whether something gains traction or not, depending on time of day and audience that happens to be online.
Okay, I don't in general see "duplicate" as implying this, but I take your point, and was wondering if that might be the etiquette here.
I also think, on reflection, that you are right in this particular case (given there are no comments on the previous duplicate) so, thank you also for clarifying.
I suppose in the future an e.g. "[Previous discussion]" tag would be more appropriate, providing comments were made, otherwise, just say nothing and leave it to HN.