Include <unistd.h>. On some systems,

it is required for the definition of _SC_PAGESIZE.

diff --git a/m4/c-stack.m4 b/m4/c-stack.m4
index 01c9a88..a58cde0 100644 (file)
--- a/m4/c-stack.m4
+++ b/m4/c-stack.m4
@@ -1,6 +1,6 @@
 # Check prerequisites for compiling lib/c-stack.c.
 
-# Copyright (C) 2002 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2003 Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -27,6 +27,7 @@ AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC],
      ac_cv_sys_xsi_stack_overflow_heuristic,
      [AC_TRY_RUN(
        [
+        #include <unistd.h>
         #include <signal.h>
         #include <ucontext.h>