Re: [ANNOUNCE] GHC 8.2.2 release candidate 1

I would have guessed that it's actually due to #11963 [1], and consequently, this [2] backported patch. Ryan S. ----- [1] https://ghc.haskell.org/trac/ghc/ticket/11963 [2] http://git.haskell.org/ghc.git/commit/18dee8912f6afdcf13073d3d95d85513c14180... On Oct 1, 2017 21:19, "Ben Gamari" wrote:

Ryan Scott writes:

...

I did a smoke test of Stackage Nightly's libraries [1] this afternoon using GHC 8.2.2. Only two libraries failed to build: extensible-0.4.5 and protolude-0.2, due to a change where type signatures like `foo :: forall k. forall (a :: k). ...` no longer compile without enabling TypeInType.

I only mention this because the migration guide for 8.4 [2] currently gives the impression that this TypeInType change won't land until GHC 8.4. This doesn't appear to be case, though!

It sounds like you are describing #13391. If this is the case then I'm rather confused since I didn't merge the associated patch. Something else must be going on here. Perhaps some other patch made the checks a bit more strict inadvertently?

Cheers,

- Ben