+AC_SUBST([guileobjectdir])
+
+dnl The GnuTLS bindings are necessary for substitutes over HTTPS and for 'guix
+dnl pull', among other things.
+GUILE_MODULE_AVAILABLE([have_gnutls], [(gnutls)])
+if test "x$have_gnutls" != "xyes"; then
+ AC_MSG_ERROR([The Guile bindings of GnuTLS are missing; please install them.])
+fi