[Nix-dev] Build dependent haskell packages

[lewo at abesis.fr]

hi Peter,

> what version of NixOS do you use? The "ghc7.8.3-0.12-shared" bit of the
> package name suggests it's something rather old.

Exactly, it's something rather old since I'm using 14.12.

>  >   {
>  >     packageOverrides = pkgs: rec {
>  >       haskellPackages = with pkgs.haskellPackages; pkgs.haskellPackages // rec {
>  >           xmonad = callPackage /home/lewo/repos/xmonad {};
>  >           xmonadContrib = callPackage /home/lewo/repos/XMonadContrib {};
>  >       };
>  >     };
>  >   }
>
> That override won't work (evidently). It replaces the value of xmonad
> that you see during "nix-env", but it won't replace the value of xmonad
> that xmonadContrib sees while binding its dependencies. The Nixpkgs
> manual covers these details in [1], but it refers to release-15.09 or
> later of Nixpkgs, I'm afraid.

I finally overrided the xmonad dependency in the xmonadContrib
callPackage function as following:
xmonadContrib = callPackage /home/lewo/repos/XMonadContrib { xmonad = xmonad };

Thanks for mentionning the dependencies binding problem at build time
since this has allowed me to solve my difficulty.

lewo.