From 5b7b91f6b3a7c455e050db12f9eb0dc25e6816af Mon Sep 17 00:00:00 2001
From: Frederik Rietdijk <fridh@fridh.nl>
Date: Mon, 1 May 2017 11:19:27 +0200
Subject: [PATCH] pythonPackages.sharedLibraryExtension

---
 pkgs/top-level/python-packages.nix | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index d6f4908d1bff..3e89d46885fd 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -67,10 +67,14 @@ let
         else throw "Unsupported kind ${kind}");
     in fetcher (builtins.removeAttrs attrs ["format"]);
 
+  # This should become part of stdenv!
+  sharedLibraryExtension = if stdenv.isDarwin then ".dylib" else ".so";
+
 in {
 
   inherit python bootstrapped-pip pythonAtLeast pythonOlder isPy26 isPy27 isPy33 isPy34 isPy35 isPy36 isPyPy isPy3k mkPythonDerivation buildPythonPackage buildPythonApplication;
   inherit fetchPypi;
+  inherit sharedLibraryExtension;
 
   # helpers