Index: gettext-tools/gnulib-lib/execute.c
--- gettext-tools/gnulib-lib/execute.c.orig	2019-01-06 13:17:03.000000000 +0100
+++ gettext-tools/gnulib-lib/execute.c	2019-12-27 12:27:20.746022000 +0100
@@ -196,6 +196,9 @@
      subprocess to exit with return code 127.  It is implementation
      dependent which error is reported which way.  We treat both cases as
      equivalent.  */
+#ifndef HAVE_ENVIRON_DECL
+  extern char **environ;
+#endif
   sigset_t blocked_signals;
   posix_spawn_file_actions_t actions;
   bool actions_allocated;