[Nix-dev] patch: add haskell package for darcs version of cabal-install

[Peter Simons]

Hi Corey,

I tried to build the latest version of cabal-install using that patch,
but the build failed with the following error message:

 | Configuring cabal-install-0.15.0...
 | Setup: At least the following dependencies are missing:
 | Cabal >=1.15.0 && <1.16

Now, Cabal version 1.15.0 is not public available, i.e. we would have to
have build that library from the Darcs repository, too, to make that
available. I'm not sure whether we should go into that direction, though.

The problem is that, right now, GHC 7.4.1 cannot build cabal-install. Since
cabal-install is an executable without any library code, it doesn't matter,
though, which compiler has built it: one can use, say

  haskellPackages_ghc704.cabalInstall

..., just fine with GHC 7.4.1. It's certainly not a good solution, though,
because users who are new to Nix won't be able to guess that.

Well, I'm not sure what to do. Opinions, anyone?

Take care,
Peter