Ask HN: Who don't Hacker News discussion threads appear in web search results?
I use Google and DuckDuckGo. The site's robots.txt file doesn't look like it does anything to preclude inclusion by the engines.
https://www.google.co.uk/search?q=%22so+you+add+%22syn_maxfa...
Possibly you were searching for a thread that was too recent to have been indexed?
> ...too recent to have been indexed? The opposite, actually. For example, I'd think that searching Google for "disrespect CasperJS or PhantomJS" would, at a minimum, return this discussion from a year back: