GNU Coreutils: Allow builds with newer versions of glibc.

pkgs/tools/misc/coreutils/default.nix

@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
     ++ stdenv.lib.optional selinuxSupport libselinux
     ++ stdenv.lib.optional selinuxSupport libsepol;
 
-  crossAttrs = {
+  crossAttrs = ({
     buildInputs = [ gmp ]
       ++ stdenv.lib.optional aclSupport acl.hostDrv
       ++ stdenv.lib.optional selinuxSupport libselinux.hostDrv
@@ -32,7 +32,14 @@ stdenv.mkDerivation rec {
     # I don't know why it is not properly detected cross building with glibc.
     configureFlags = [ "fu_cv_sys_stat_statfs2_bsize=yes" ];
     doCheck = false;
-  };
+  }
+
+  //
+
+  # XXX: Temporary workaround to allow GNU/Hurd builds with newer libcs.
+  (stdenv.lib.optionalAttrs (stdenv.cross.config == "i586-pc-gnu") {
+    patches = [ ./gets-undeclared.patch ];
+  }));
 
   # The tests are known broken on Cygwin
   # (http://thread.gmane.org/gmane.comp.gnu.core-utils.bugs/19025),