[Nix-dev] minor snag building in stdenvNative

[Brian Gough]

In pkgs/tools/text/gnupatch/default.nix there's a reference to the
file ftp://alpha.gnu.org/gnu/patch/patch-2.6.1-2-g2c4e3ec.tar.gz which
no longer exists on alpha.gnu.org.  

The comment says the patched version was only needed for Darwin, but
the test also catches stdenvNative on any platform (I think).  The
patch below adds a check for .isDarwin so that the build doesn't fail
unnecessarily on other platforms.

-- 
Brian Gough

Index: pkgs/tools/text/gnupatch/default.nix
===================================================================
--- pkgs/tools/text/gnupatch/default.nix	(revision 21310)
+++ pkgs/tools/text/gnupatch/default.nix	(working copy)
@@ -4,7 +4,7 @@
   name = "patch-2.6.1";
 
   src =
-    if !(stdenv ? glibc)
+    if (stdenv.isDarwin && !(stdenv ? glibc))
     then fetchurl {
       # Temporary fix for
       # http://lists.gnu.org/archive/html/bug-patch/2010-01/msg00004.html .