Issue installing Snap on macOS Sierra

Question

I\'m having trouble installing the Haskell framework Snap on macOS Sierra. Whenever I install it, I get the following message:

Resolving dependencies...
Con         


        

Answer 1

There was an issue with full 8.2.1 binary platform builds that's just been resolved: https://mail.haskell.org/pipermail/haskell-cafe/2017-October/127979.html

This was likely an instance of that.

(see also: GHC cannot find libraries on fresh install of Haskell-Platform)

Answer 2

This looks like a bug in Cabal 2 (or potentially GHC 8.2). See https://github.com/haskell/cabal/issues/4728. I'd recommend sticking to GHC 8.0.2 for the moment with either cabal 1.24 or Stack. I'm the case of Stack, the version won't matter, since it will use the Cabal version shipped with GHC.