This is necessary to get things building again after libselinux changes.
A proper fix is under discussion upstream:

  <https://sourceware.org/pipermail/libc-alpha/2020-July/116504.html>

diff --git a/nss/makedb.c b/nss/makedb.c
index 8e389a1683747cf1..9d81aed57d384a22 100644
--- a/nss/makedb.c
+++ b/nss/makedb.c
@@ -17,6 +17,10 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+/* This file uses deprecated declarations from libselinux.  */
+#include <libc-diag.h>
+DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
+
 #include <argp.h>
 #include <assert.h>
 #include <ctype.h>