Currently stable ghc in main is ancient. Since most of the haskell-packages are in the haskell overlay, for haskell users it is common to live on bleeding edge and use everything keyworded from the haskell overlay as default. Yet, the most crucial item in the Haskell landscape is GHC. A chat with geekosaur in IRC revealed that not the currently released GHC is the generally upstream-supported version but what can be obtained via http://www.haskell.org/platform. Considering that the current GHC in stable is ancient and 7.6 is considered "bleeding edge" by Haskell folks i propose tracking what is currently provided by platform as stable - either in the overlay or (preferrably) in main. Reproducible: Always
*** This bug has been marked as a duplicate of bug 457780 ***