[Nix-dev] ghc wrapper, and the 'binary' package

[Peter Simons]

Hi Mathijs,

the build problems in xmonad-extras are now fixed. Fixing uhc is
trickier though:

  > The way this is checked by the configure script is by just calling
  > "ghc-pkg list --simple-output binary".
  >
  > I haven't investigated nix's cabal-hooking a lot, as it mostly "just
  > works". I see it's using a little wrapper to point ghc to all installed
  > packages, but my package list indeed doesn't show any core libraries
  > (the ones inside the ghc derivation).

This is a known bug in the GHC wrapper. It should be fixed, but somehow
nobody seems to be doing it. If it's possible to patch uhc to recognize
the binary library in another way (or just not test for it at all
because we know it exists), then that would be a good solution for use
in Nixpkgs.

Take care,
Peter