Handle .hsc files

[basvandijk]

Cabal automatically handles .hsc files. It would be cool if snack could also handle these files.

One particularly complex project that also uses hsc2hs is haskell-opencv. Besides hsc2hs it also uses inline-c and it depends on a C++ library. It might be a nice challenge to see if snack is able to build it.

To do a non-snack build you can simply do:

git clone [email protected]:LumiGuide/haskell-opencv.git
cd haskell-opencv
nix-build -A haskellPackages.opencv