Examples where old Hoogle 4 does worse than new Hoogle 5
The die in System.Exit does not come up when you search for "die" on haskell.org/hoogle (Hoogle 4). Searching for other things in System.Exit, e.g. exitFailure, works.
Try http://hoogle.haskell.org/?hoogle=die - which is the new Hoogle 5 instance. I'm working on obtaining feature parity, then I'll be adding a redirect.
Oh, cool! So I guess this ticket should be closed, or marked as "fixed in Hoogle 5" somehow?
No idea - things are in flux and I have no real idea how things should be marked until Hoogle 5 is out, and then I'll go through and fix most of the tickets as done. As a result, the bug tracker is going to be a bit messy until then.
And similarly, readMaybe and readEither in Text.Read aren't found in Hoogle 4, when searching by name or by type. The Hoogle 5 finds them.
Issue #180 has examples where Hoogle 5 gives the wrong answer or does worse than Hoogle 4.