We should strengthen the thread necromancy warning

The convention on this forum is that you usually shouldn't revive old threads unless you are directly following up on the previous thread. To use two recent examples, reviving a thread about the force unwrap fix-it makes sense because the new post explains how the issue has been addressed. However, reviving a thread pitching generic protocols to point out a tangential use case would be discouraged.

(I don't mean to pick on the author of that post—someone or another does this every week or so. This is just the most recent example.)

We've previously discussed auto-locking old threads, but I think that's too strong a measure—sometimes, like the force-unwrap fix-it thread, it really is appropriate to revive an old topic. But I think the wording of the current warning is too gentle:

Revive this topic?

The last reply to this topic was 9 months ago. Your reply will bump the topic to the top of its list and notify anyone previously involved in the conversation.

Are you sure you want to continue this old conversation?

And we should probably strengthen it to something like:

Revive this topic?

The last reply to this topic was %{time_ago}. Don't revive it unless all of the previous participants would want to be notified of your new reply.

Instead, start a new topic and link to this topic in your post.


Pardon me for inconvenience. Indeed I was supposed to create a new thread, but it was appeared on right panel thus I thought it means I must reply on that thread instead of creating a new one. Also it’s common that someone would remind that there was an old thread that discussed the same issue and the new thread is redundant.

I don't think thread necromancy is a bad thing. I'd much rather that, when old topics are revisited, we continue the existing discussion rather than start new threads, so that it's easier to refer to the discussion from proposals or related feature discussions, and for popular topics like generics features we don't keep reiterating the same points every few months.


While there are some benefits, there are two large problems with thread necromancy:

First, for participants in the original thread, these updates cause the thread to show up just as any other with a recent update. One starts reading from the top, then two paragraphs in, one realizes that the text is three years old. Then one scrolls to the bottom and realizes that the new message makes no sense out of context anyway. It'd be much nicer in terms of inviting participation from former participants in a topic to start with a new thread where the poster does a bit of legwork to summarize the context as they know it; previous participants can meet them half-way by filling in the gaps.

Second, for non-participants in the original thread, I don't think these updates show up at all unless you're automatically "watching" every single post. That's a lot of watching. People who subscribe to be notified of major goings-on won't see a resurrected thread, no matter how hot the topic. All because three years ago they didn't particularly have something to say about it, or because they weren't around then. For these people, too, it'd be much nicer in terms of feeling invited to participate if they saw a fresh thread with a succinct summary than a mass of hundreds of posts from three years ago (should they stumble on the thread at all).