https://bugs.gentoo.org/385091

https://lists.gnu.org/archive/html/bug-readline/2011-10/msg00000.html

--- a/examples/rlfe/configure
+++ b/examples/rlfe/configure
@@ -4062,6 +4062,7 @@ cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 
+extern char *tgoto(char *, int, int);
 main()
 {
  exit(strcmp(tgoto("%p1%d", 0, 1), "1") ? 0 : 1);