Merge 'staging' into closure-size

- there were many easy merge conflicts
- cc-wrapper needed nontrivial changes

Many other problems might've been created by interaction of the branches,
but stdenv and a few other packages build fine now.

pkgs/tools/archivers/gnutar/default.nix

@@ -1,16 +1,27 @@
-{ stdenv, fetchurl, acl }:
+{ stdenv, fetchurl, autoreconfHook, acl }:
 
 stdenv.mkDerivation rec {
   name = "gnutar-${version}";
-  version = "1.27.1";
+  version = "1.28";
 
   src = fetchurl {
     url = "mirror://gnu/tar/tar-${version}.tar.bz2";
-    sha256 = "1iip0fk0wqhxb0jcwphz43r4fxkx1y7mznnhmlvr618jhp7b63wv";
+    sha256 = "0qkm2k9w8z91hwj8rffpjj9v1vhpiriwz4cdj36k9vrgc3hbzr30";
   };
 
+  patches = stdenv.lib.optional stdenv.isDarwin ./gnutar-1.28-darwin.patch;
+
+  # gnutar tries to call into gettext between `fork` and `exec`,
+  # which is not safe on darwin.
+  # see http://article.gmane.org/gmane.os.macosx.fink.devel/21882
+  postPatch = stdenv.lib.optionalString stdenv.isDarwin ''
+    substituteInPlace src/system.c --replace '_(' 'N_('
+  '';
+
   outputs = [ "out" "info" ];
-  buildInputs = [ acl ];
+
+  buildInputs = [ acl ]
+    ++ stdenv.lib.optional stdenv.isDarwin autoreconfHook;
 
   # May have some issues with root compilation because the bootstrap tool
   # cannot be used as a login shell for now.