Revert "Merge pull request #9543 from NixOS/staging.post-15.06"

This reverts commit f61176c539, reversing
changes made to a27ca029ee.

Conflicts:
	pkgs/development/libraries/ncurses/default.nix

pkgs/development/interpreters/ruby/bundler-env/default-gem-config.nix

@@ -20,7 +20,7 @@
 { lib, fetchurl, writeScript, ruby, libxml2, libxslt, python, stdenv, which
 , libiconv, postgresql, v8_3_16_14, clang, sqlite, zlib, imagemagick
 , pkgconfig , ncurses, xapian, gpgme, utillinux, fetchpatch, tzdata, icu, libffi
-, cmake, libssh2, openssl, mysql, darwin
+, cmake, libssh2, openssl, mysql
 }:
 
 let
@@ -70,7 +70,6 @@ in
       "--with-exslt-lib=${libxslt}/lib"
       "--with-exslt-include=${libxslt}/include"
     ] ++ lib.optional stdenv.isDarwin "--with-iconv-dir=${libiconv}";
-    buildInputs = lib.optional stdenv.isDarwin darwin.libobjc;
   };
 
   pg = attrs: {
@@ -120,10 +119,6 @@ in
     '';
   };
 
-  unf_ext = attrs: {
-    buildInputs = lib.optional stdenv.isDarwin darwin.libobjc;
-  };
-
   xapian-ruby = attrs: {
     # use the system xapian
     buildInputs = [ xapian pkgconfig zlib ];