[Nix-dev] Patch for pythonPackages.numpy

[Peter Simons]

Hi Konrad,

 > Building NumPy on MacOS fails with the current state of nixpkgs, and I
 > suspect it can fail on other platforms as well, as the problems I found
 > are not specific to MacOS. With the attached patch, it builds correctly,
 > at least under MacOS.

I applied your patch in r33941, but that change caused build failures
for matplotlib on Linux (and probably on other platforms as well which
Hydra doesn't automatically check):

  http://hydra.nixos.org/build/2490567

Do you by chance know how to fix these problems?

If in doubt, I'd rather revert that patch again, because it doesn't seem
to improve matters.

Take care,
Peter