[Nix-dev] Re: Ruby-gems

[Pjotr Prins]

Back on the old topic. I am having a problem with recursion.

On Sun, Aug 03, 2008 at 01:56:48PM -0700, Aaron VonderHaar wrote:
> As for system-wide gems, I wonder if it might not be appropriate to  
> add a configuration option to the ruby or gems package which lists a  
> set of gems to install, just as nixos has  
> "environment.extraPackages".  The gems package could then install all  
> the necessary gems as the last step of its install process, and the  
> result would be unique to it's hash.

I am trying to do this (for R). The derivation looks like:

stdenv.mkDerivation {
  name = "r-lang";
  version = "2.7.0";
  src = fetchurl {
    url = http://cran.r-project.org/src/base/R-2/R-2.7.0.tar.gz;
    sha256 = "17ql1j5d9rfpxs04j9v9qyxiysc9nh6yr43lgfdamayzjpia5jqm";
  };

  bioconductor = if withBioconductor then import ../../../development/libraries/science/biology/bioconductor { inherit fetchurl stdenv rLang ; } else null;

}

renders:

error: undefined variable `rLang', in
`/export/users/local/wrk/data/org/nixpkgs-testing-pjotr/pkgs/development/interpreters/r-lang/default.nix'

So, I am trying to build a package inside another package (rLang
refers to the surrounding package). It requires rLang to find the
library path. I am assuming the final rLang derivation will be correct
this way.

Is this assumption correct? If not, what would be a way to do the
same thing? And how do I get rid of the error?

Pj.