Thanks for the explanation; I installed the attached further patch.
>From 6ff8421cf8709b1c210b6a15118d3baa2d6685a8 Mon Sep 17 00:00:00 2001
From: Paul Eggert
Date: Sun, 16 Apr 2017 12:43:20 -0700
Subject: [PATCH] regex: port better to Solaris 10
Solaris 10 includes , which #defines
gettext, and
On Sat, Apr 15, 2017 at 02:40:49PM -0700, Paul Eggert wrote:
> Sorry, I don't understand how this could be. regex_internal.h's "#define
> gettext(msgid) msgid" line is in the else-part of the #if that #includes
> libintl.h in its then-part, so how can libintl.h's #define for gettext be
> active whe