NixOS/nixpkgs — pull request #4065 by ts468 (2014-09-13 16:01:52+00:00)
Title: Work on Haskell GHC wrapping.

- unify wrapper build by standard ghc-wrapper and by ghcWithPackages
- add caching of GHC packages search into ghc-wrapper
- add scripts to run command in an installed ghcWithPackages environment
- add flag for cabal.mkDerivation to automatically wrap binaries