Roughly what day, and what search terms have you tried? Can you remember any unusual words? How long was the thread?
Was it this one?
Was it this one?
Sadly, it was not this language, but thank you for the link
https://news.ycombinator.com/best
You can also look at the front page from a specific day here:
https://news.ycombinator.com/front?day=2020-04-08
Through that I found this item:
Clojure: https://news.ycombinator.com/item?id=22797858
And this:
The language is called Pointless: https://ptls.dev/. It appears to be a scripting language with functional programming ideologies.