Continuing the discussion from Hoogle appears to be down:
The domain stackage-haddock.haskell.org
is malfunctioning right now.
This domain hosts Haddocks for Stackage (random example: Text.XML.HXT.TagSoup), which are thus broken.
It also hosts https://stackage-haddock.haskell.org/snapshots.json, which Stack frequently fetches in the course of normal operation.
So things are pretty broken until this gets fixed. I’m working on it…