GNU Nettle: Tentative patch for Cygwin.

svn path=/nixpkgs/trunk/; revision=17250

pkgs/development/libraries/nettle/cygwin.patch

···
+Cygwin sucks.  Patch suggested by Niel Möller.
+
+--- nettle-2.0/examples/setup-env	2009-06-08 20:27:12.000000000 +0200
++++ nettle-2.0/examples/setup-env	2009-09-18 16:58:03.000000000 +0200
+@@ -3,5 +3,5 @@
+ set -e
+ 
+ if [ -x rsa-keygen ] ; then
+-  ./rsa-keygen -r rsa-decrypt -o testkey || exit 1
++  ./rsa-keygen -r rsa-decrypt.exe -o testkey || exit 1
+ fi
+

pkgs/development/libraries/nettle/default.nix

···
 
   doCheck = true;
 
+  patches = stdenv.lib.optional (stdenv.system == "i686-cygwin")
+              ./cygwin.patch;
+
   meta = {
     description = "GNU Nettle, a cryptographic library";